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Management Information Systems: Solving Business Problems with Information Technology, 3/e
Gerald V. Post, University of the Pacific
David L. Anderson, DePaul U/McGowan Center


10Base-T  A system of connecting computers on a LAN using twisted-pair cable. The method relies on compression to increase raw transfer rates to 10 megabits per second.
Access speed  A measure of disk drive speed. Loosely, the time it takes a disk drive to move to a particular piece of data.
Accounting journal  Raw financial transaction data are collected by the accounting department and stored in a journal. Modern accounting requires the use of a double-entry system to ensure accurate data.
Activity-based costing (ABC)  ABC allocates costs by examining a detailed breakdown of the production activities. The cost of each process is computed for each different product. The detail provides a better picture of the production cost for each item.
Advanced encryption standard (AES)  A new U.S. standard for single-key encryption; approved in 2001 by the government to replace DES and triple DES. With 128 bit keys, it is substantially more difficult to break, but still very fast to encrypt and decrypt.
Advocacy role  Someone in MIS, usually the chief information officer, who bears responsibility for exploring and presenting new applications and uses of MIS within the company.
Agent  An object-oriented program designed for networks that are written to perform specific tasks in response to user requests. Agents are designed to automatically communicate with other agents to search for data and make decisions.
American National Standards Institute (ANSI)  An organization responsible for defining many standards, including several useful information technology standards.
American Standard Code for Information Interchange (ASCII)  A common method of numbering characters so they can be processed. For instance, the letter A is number 65. It is slowly being replaced by the ANSI character set table and the use of international code pages that can display foreign characters.
Angel investor  An individual who provides a limited amount of funding to startup firms. Unlike a partner, the investor is rarely involved in management. The amount of funding is generally small-$25,000 to $100,000.
Antitrust laws  A variety of laws that make it illegal to use monopoly power. Some basic (economic) actions to achieve a competitive advantage are illegal. Strategic plans must be evaluated carefully to avoid violating these laws.
Application service provider (ASP)  A specialized Internet firm that provides an individual application to other businesses. For example, a reservation system can be run by an ASP to provide services to other companies.
Artificial intelligence (AI)  An attempt to build machines that can think like humans. Techniques evolved from this research help solve more complex problems. Useful techniques include expert systems, neural networks, massively parallel computers, and robotics.
Assumptions  Models are simplifications of real life, so they require assumptions about various events or conditions.
Asynchronous Transfer Mode (ATM)  A packet-based network system that uses high-speed transmission lines (150 megabits and over) and routers to maximize network efficiency and throughput.
Attributes  Descriptions of an object or entity. For example, a customer object would at least have attributes for name, phone number, and address.
Auction  In an e-commerce context, a Web-based system where individuals bid for items. Useful when you do not know the exact value of an item, or have only a few items to sell. The auction site helps handle payments but charges a percentage fee.
Audit trail  The ability to trace any transaction back to its source. In accounting, transaction values are accumulated on the general ledger and used to create reports. An audit trail is a set of marks or records to point back to the original transaction.
Authentication  The ability to verify the source of a message. Dual-key systems are a useful technique. Uses a private key to encrypt the message. The recipient applies the sender's public key. If the decrypted message is readable, it had to have come from the alleged sender, because the keys always work in pairs.
Backbone  A high-speed communication line that links multiple sub networks. It is usually a fiber-optic line.
Backward chaining  In an expert system, the user enters a "conclusion" and asks to see whether the rules support that conclusion.
Barriers to entry  Anything that makes it more difficult for new firms to enter an industry. Several possibilities would violate antitrust laws. An acceptable barrier is the increased use of information systems, which raises the cost of entering an industry because a rival would have to spend additional money on information technology.
Beginners All-purpose Symbolic Instruction Code (BASIC)  An early computer programming language designed to be easy to program and to teach. Visual Basic is a current version for Windows programming.
Benchmark  A set of routines or actions used to evaluate computer performance. By performing the same basic tasks on several machines, you can compare their relative speeds. Benchmarks are especially useful when the machines use different processors and different input and output devices.
Bill presentation and payment  Web-based software that automatically displays bills and invoices for customers. The payment side accepts various forms of payment including credit cards and electronic checks. Generally run as a Web service.
Binary data  A collection of ones and zeros called bits. Computer processors operate only on binary data. All data forms are first converted to binary.
Biometrics  A field of study that is trying to determine how to identify people based on biological characteristics. The most common devices are fingerprint and handprint readers.
Bit  The smallest unit of data in a computer. All data is converted to bits or binary data. Each bit can be in one of two states- on or off. Bits are generally aggregated into collections called a byte.
Bitmap image  A method of storing images. The picture is converted to individual dots that are stored as bits. Once a picture is stored in bitmap form, it is difficult to resize. However, bitmaps are good for displaying photographic images with subtle color shading.
Board of directors  A group of people paid to oversee and evaluate the decisions of the company. Technically the CEO reports to the board of directors, but they are charged more with reviewing the CEO's decisions. Most boards have the authority to remove a CEO, but many board members are selected by the CEO.
Boolean search  Searching for data by using the logic operators AND, OR, and NOT conditions in a WHERE statement, for example, find a list of customers where city = "Detroit" and age > 50 and do not own a car.
Bottom-up development  An approach to designing and building systems in which workers build system components to solve each problem as it arises. Eventually the pieces are combined to create an integrated system. The method relies on standards and controls to facilitate cooperation and integration. See also Top-down development.
Brainstorming  A group technique in which each individual is asked to come up with possible suggestions to a problem. Any ideas are useful, regardless of how wild they are. Even fanciful ideas could stimulate someone else to improve it or to explore a related area.
Broadcasts  A technique of transmitting messages using radio, micro, or infrared waves. Broadcast messages are sent to all devices in a certain area. Others in the vicinity can also receive the messages.
Browser  A software tool that converts World Wide Web data into a graphical page with hypertext links. Using standard (HTML) commands, companies can offer data and additional links to users. Users simply click on individual words and pictures to retrieve additional data and move to other network sites.
Brute force  An attack on encrypted data that attempts to guess every possible key. Can be stopped by using very long keys. Example, using a key or password of only three letters means there are only 26*26*26 = 17,576 possible values. Even a slow computer can test all combinations in a few seconds.
Bulletin board system (BBS)  Similar to a typical bulletin board, except that people access it from computers. The BBS enables users to store comments, pictures, and files for other people to retrieve. Bulletin boards are usually organized by topics and can be searched for specific phrases or comments. They are useful way to disseminate information that is of interest too many different people.
Bus  Most computers have special slots called a bus to provide high-speed connections to other devices. Various manufacturers make boards that fit into these slots. The processor can exchange data with these other devices, but performance is sometimes constrained by the design of the bus.
Business to business (B2B)  Business-to-business electronic commerce; sales by suppliers to other businesses over the Internet; often long-term relationships. See B2C and EDI.
Business to consumer (B2C)  Business-to-consumer electronic commerce, purchases by individual consumers similar to traditional mail-order systems, but conducted on secure web-sites over the Internet.
Bus network  A network organizing scheme in which each computer is attached to a common transmission medium. Protocols are needed to determine when a machine can transmit and to recover from collisions.
Byte  A collection of bits. Traditionally, 8 bits make up one byte. From binary arithmetic, an 8-bit byte can hold 2 to the 8th power, or 256, possible numbers. In many systems a byte is used to hold one character.
C  A powerful programming language that is flexible and creates efficient code. A language commonly used to build complex applications, and to create commercial software products.
C++  An object-oriented extension of the C programming language. It is commonly used to build commercial software. It produces efficient code and supports the development of reusable objects.
Cable modem  An Internet connection device that translates local area network protocols to turn over a television cable line. It can provide transmission speeds around 3 Mpbs. the communication line is shared with other users.
Cache  A buffer between the processor and a slower device such as a printer, disk drive, or memory chips. The cache generally consists of high-speed memory. Data is transferred in bulk to the cache. It is then pulled out as it is needed, freeing up the processor to work on other jobs instead of waiting for the slower device to finish.
Carrier-Sense, Multiple-Access/Collision Detection (CSMA/CD)  A communications protocol that determines how computers will behave on a shared-medium network. Ethernet protocols rely on CSMA/CD. Other alternatives are Token Ring and packet switching.
Case-based reasoning  An expert system approach that records information in the form of situations and cases. Users search for cases similar to their current problem and adapt the original solution.
CD-ROM  Compact disk-read only memory. Data is stored and retrieved with a laser. A special machine is required to create data on a CD-ROM. Used to hold data that does not change very often. Useful for multimedia applications because a disk can hold about 650 megabytes of data. The format used to store music CDs.
Centralization  A business scheme for performing most operations and making management decisions from one location in an organization. MIS organization can be examined in four areas- hardware, software, data, and personnel. See also Decentralization.
Certificate authority (CA)  Dual-key encryption and authentication require that the public key be published and available to others. A certificate authority is an organization that validates the owner's identity, issues the keys, and runs the public directory. Almost anyone can run the software to be a CA, but others must trust that host.
Change agents  Objects or people who cause or facilitate changes. Sometimes the change agent might be a new employee who brings fresh ideas, other times change can be mandated by top-level management. Sometimes an outside event such as a competitor or a hurricane forces an organization to change.
Change drivers  Concepts or products that have altered the way businesses operate. Classic examples include- bar-code scanners in retail stores, handheld mini-terminals or notebooks by delivery firms and salespeople, and reservation systems by travel and entertainment industries.
Charge-back system  A scheme for charging other internal departments for services. For example, some firms charge departments a fee based on how often they use the central computer. The goal was to ration a limited resource by avoiding free use.
Chart of accounts  A listing of all of the accounts and sub accounts in the general ledger. It must be defined ahead of time for each business.
Chief executive officer (CEO)  The head of a company. The person ultimately responsible for setting the direction and policies of the firm. Usually the CEO is also the chairperson of the board of directors.
Chief information officer (CIO)  The person who is in charge of the MIS organization within a firm, charged with overseeing operations, setting MIS priorities, and being a top-level-advocate for MIS. Also develops and supports strategy for the firm.
Circular reference  In a spreadsheet, a set of cells that eventually refer to each other. In the simplest example, cell A1 would use values stored in cell A2, but cell A2 uses the value stored in A1. This technique is sometimes used to create an iterative solution to a model.
Classes  Base descriptions of objects. Technically, classes describe generic attributes and methods. Objects are a specific instance of a class.
Click-through rate  Used in Web advertising, the percentage of people viewing an online ad who actually click it to see the details on the advertised product or service. By 2000, the average click-through rates had declined to less than 1 percent. But it is not necessarily a good measure of advertising effectiveness.
Client-server network  A network configuration in which a few machines are used as file servers and the others (clients) are independent workstations. Shared data is first sent to a file server where it can be examined or transferred by another client.
Client-server organization  A method of organizing the MIS function so that some operations are centralized while others are decentralized. The client-server model separates all of the components into two categories servers or clients. The functions associated with the server tend to be centralized, whereas the client components and tasks are dispersed among the users.
Clip art  Artwork created and sold to be used by non-artists. Hundreds of collections are available of people, places, buildings, and other objects. Clip art images are often used to create presentations and illustrate reports.
Clipboard  The method used to transfer data between software packages in windows-oriented operating environments. All objects that are cut or copied are placed onto the clipboard, ready to be pasted to another location or another package. Clipboard viewers exist to show the current contents of the clipboard. Some software systems allow a clipboard to hold several cuttings. Many automatically delete the older cuts-keeping only the most recent.
Clipper chip  An encryption method created by the U.S. top-secret National Security Agency (NSA). Secret algorithm to encrypt and decrypt digital messages. It was particularly designed for digital voice communication. Its key feature is the use of two escrow keys assigned to each chip. If the police decide they want to listen to a conversation between two suspects, they can get a court order, collect the escrow keys and instantly decrypt the call.
Closed loop  A system or piece of computer code in which every step in a control mechanism is contained inside the system, and does not utilize external input. See also Feedback.
Closed system  A system that is entirely self-contained and does not respond to changes in the environment. Most closed systems eventually fail due to entropy.
Coaxial cable  A cable used to transmit data. Able television is a widespread application. The inner cable is surrounded by a plastic insulator, which is surrounded by a wire mesh conductor and an outer casing. The wire mesh insulates the internal signal wire from external interference.
Cold site  A facility that can be leased from a disaster backup specialist. A cold site contains power and telecommunication lines but no computer. In the event of a disaster, a company calls the computer vendor and begs for the first available machine to be sent to the cold site.
Collision  In networks, a collision arises when two computers attempt to broadcast messages at the same time. The network protocols need to identify the situation and determine which machine will go first.
Column  A vertical part of a table that holds data for one attribute of an entity in a database or spreadsheet. For example, a table to describe automobiles will have columns for make, model, and color.
Command-line interface  A method of controlling the computer by typing commands. The user must generally memorize specific commands. Older machines still use them because GUI systems require too much overhead. Some people prefer command lines, because it is faster to type one or two commands than to manipulate an image on the screen.
Commerce server  A software system that runs an e-commerce Web server. It handles the product catalog, searching, a shopping cart, and the payment mechanism. Several vendors sell versions to be run on your own server, or you can lease space on a hosting company.
Commercial off-the-shelf software (COTS)  Purchased software for building applications. Relatively popular because it is faster than building from scratch.
Common Business-Oriented Language (COBOL)  An early programming language designed to handle typical transaction processing tasks. Its death has been predicted for years, but it is hard to throw away billions of lines of code.
Common Object Request Broker Architecture (CORBA)  A model largely developed in the UNIX community that will enable objects to communicate with each other across networks. In particular, it is designed to enable users to combine different data types from various software vendors into a single compound document. The data could reside on any server on the network.
Competitive advantage  Something that makes your company better or stronger than your rivals. Examples include Glossary 589 lower costs, higher quality, strong ties to loyal customers, and control over distribution channels.
Composite key  In relational databases, a key that consists of more than one column. The columns are combined to yield a unique primary key.
Compound document  A document that incorporates different types of data- text, graphics, sound, and video. The different objects might be transmitted across a network to be included in a final document.
Computer-aided design (CAD)  Programs that are used to create engineering drawings. CAD programs make it easy to modify drawings. They also make it easier to keep track of material specifications. They can perform spatial and engineering estimates on the designs, such as surface or volume calculations.
Computer-aided software engineering (CASE)  Computer programs that are designed to support the analysis development of computer systems. They make it easier to create, store, and share diagrams and data definitions. Some versions even generate code. There are two categories of CASE tools- software development and maintenance of existing systems.
Computer ethics  The concept that all of us have an obligation with respect to data. For example, managers have a responsibility to customers to protect personal data, to collect only data that is truly needed, and to give customers the ability to correct errors in personal data.
Computer information system (CIS)  See Management information system (MIS).
Computer-integrated manufacturing (CIM)  Using a computer to control most of the production equipment in a manufacturing environment. The computer can monitor the production statistics. It is also used to set individual machine controls.
Concurrency  A situation that arises when applications attempt to modify the same piece of data at the same time. If two people are allowed to make changes to the same piece of data, the computer system must control the order in which it processes the two requests. Mixing the two tasks will result in the wrong data being stored in the computer.
Context diagram  The top level of data flow diagram that acts as a title page and displays the boundaries of the system and displays the external entities that interact with the system.
Converge  The ability of an iterative model to stabilize on a fixed solution. The alternative is that values continually increase and never reach a solution.
Cookies  Small test files that a Web server sends to client computers. When the user returns to a site, the browser automatically returns the cookie file. Servers use them to keep track of transactions-so they know when the same user has returned. Marketers have used them to track individual users on the Web.
Copyright  A legal ownership right granted to the creators of intellectual property. All works are automatically copyrighted. Registering with the copyright office is not required but grants additional protection to the owner.
Critical success factors  A limited number of concrete goals that must be met for the organization to be successful. Identifying these key factors helps determine the strategic directions and highlights the areas that can benefit from improved information systems.
Customer relationship management (CRM)  A system for tracking and integrating all customer data. Salespeople, managers, and clerks all have access to the same data, so everyone has the same consolidated view of all customer interactions.
Cut, copy, paste  A common mechanism used to transfer and link data between different software packages. The data to be transferred is marked. When it is cut or copied, it is placed on the clipboard. Switching to the second package, the object is pasted into the appropriate location. Dynamic and static links are specified through options in the "paste special" menu.With the cut option, the original object is deleted. With copy, the original is unchanged.
Data  Consists of factual elements (or opinions or comments) that describe some object or event. Data can be thought of as raw numbers.
Data administrator  MIS manager who is charged with overseeing all of the data definitions and data standards for the company to ensure that applications can share data throughout the company.
Database  A collection of related data that can be retrieved easily and processed by computers; a collection of data tables.
Database administrator (DBA)  (1) A person appointed to manage the databases for the firm. The DBA needs to know the technical details of the DBMS and the computer system.The DBA also needs to understand the business operations of the firm. (2) A management person in the MIS department charged with defining and maintaining the corporate databases. Maintaining data integrity is a key component of the job.
Database management system (DBMS)  Software that defines a database, stores the data, supports a query language, produces, reports, and creates data-entry screens.
Data dictionary  Contains all of the information to explain the terms used to define a system. Often includes report descriptions, business rules, and security considerations.
Data encryption standard (DES)  An older method of encrypting data was commonly used by financial institutions.With current computer capabilities that can break a DES encrypted message, DES is no longer considered a secure encryption system.
Data flow diagram (DFD)  A diagramming technique used to analyze and design systems. It shows how a system is divided into subsystems and highlights the flow of data between the processes and subsystems. It displays processes, external entities, files, data flows, and control flows.
Data independence  Separating programs from their data definition and storage. The main advantage is that it is possible to change the data without having to change the programs.
Data integrity  (1) A concept that implies data is as accurate as possible. It means the database contains few errors. (2) Keeping data accurate and correct as it is gathered and stored in the computer system.
Data mart  A small version of a data warehouse. A database designed to hold concise collections of data for retrieval and analysis by managers.
Data mining  An automated system that examines data for patterns and relationships. Partly based on statistics, but it also searches for more specific associations. The results are not always applicable to other situations.
Data mirroring  The ultimate backup technique where all data that is stored on one machine is automatically transferred and stored on a second computer. Useful to prevent loss of data and recover from disasters-particularly when the second computer is located many miles away.
Data store  A file or place where data is stored. In a realistic setting, a data store could be a computer file, file cabinet, or even a reference book.
Data types  To humans, there are four basic types of data- text and numbers, images, sound, and video. Each data type must be converted to binary form for computer processing.
Data warehouse  A single consolidation point for enterprise data from diverse production systems. The data is typically stored in one large file server or a central computer. Because legacy systems are difficult to replace, some data is copied into a data warehouse, where it is available for management queries and analysis.
Decentralization  Moving the major operations and decisions out to lower levels within the firm. In MIS, decentralization has largely been led by the declining cost and improved capabilities of personal computers. See also Centralization.
Decision biases  Without models and careful analysis, decisions made by people tend to be biased. There are several biases in each of the four systems categories- data acquisition, processing, output, and feedback.
Decision support system (DSS)  System to use data collected by transaction-processing systems to evaluate business models and assist managers in making tactical decisions. There are three major components- data collection, analysis of models, and presentation.
Decision tree  A graphical representation of logic rules. Each possible answer to a question or situation leads to a new branch of the tree.
Decision process  The steps required to make a decision. It includes problem identification, research, specification of choices, and the final selection. Midlevel managers are often involved in the initial stages and affect the outcome, even though they may not make the final decision.
Default value  A value that is automatically displayed by the computer. Users can often override the default by deleting the old value and entering a new one. The goal is to choose a value that will almost always be entered, so the user can skip that item.
Dehumanization  Some people feel that technology isolates people and decreases our contact with other members of society. Treating people as identification numbers and summary statistics can lead managers to forget the human consequences of their decisions.
Denial of service (DoS)  Preventing legitimate users access to systems and networks. A common Internet trick is to force thousands of zombie computers to flood a server with millions of meaningless messages-preventing anyone else from using the system.
Descriptive model  A model that is defined in words and perhaps pictures. Relationships between objects and variables tend to be subjective. Useful for an initial understanding of a system but difficult to evaluate by computer.
Desktop publishing (DTP)  The art of creating professional documents with personal computers and small laser printers. Beyond basic word processing, DTP software provides controls to standardize pages, improve the page layout, and establish styles.
Detail section  The section in a report that is repeated for every row in the associated tables. It is often used for itemized values, whereas group and page footers are used for subtotals.
Diagnostic situations  Spotting problems, searching for the cause, and implementing corrections. Examples include responding to exception reports to identify problems and potential solutions and determining why the latest approach did not perform as well as expected.
Dial-back modem  A special modem placed on a central computer. When a user attempts to log in, the dial-back modem breaks the connection and calls back a predefined phone number. Its use minimizes the threat of outsiders gaining access to the central computer.
Digital cash  An electronic version of money that is provided and verified by a trusted third party. It consists of an encrypted number for a specified value that can only be used one time. It provides for verifiable and anonymous purchases using networks.
Digital certificate  Part of an authentication mechanism used with dual-key encryption. Companies that host servers need to encrypt transactions over the Internet. They purchase a digital certificate from a certificate authority and install it on the Web server. The client browser recognizes the certificate key and encrypts the data.
Digital dashboard  A visual presentation of broad measures of current activity in an organization. The data is generally Glossary 591 displayed as gauges, and the system must be customized for each organization. As part of an executive information system, managers can drill down to get more data.
Digital divide  The distance between those-individuals or nations-who have network capabilities and those who do not. Despite declining costs, many people and many nations cannot afford the hardware and software. If a large portion of the economy moves online, it could alienate those who cannot afford the network connection.
Digital rights management (DRM)  A combination of encryption and Internet validation for protecting vendor copyrights to prevent unauthorized copying of digital content (software, music, books, movies, and so on).
Digital signature  Any electronic signature technology that verifies the user. U.S. equivalent to handwritten ones. The most secure system is to obtain a digital certificate from a public company that verifies each person's identity. But, the IRS accepts a simple PIN issued by the agency as a digital signature.
Digital subscriber line (DSL)  A special phone service connection available to customers within three miles of the phone company's switch. It provides about 1 Mbps transmission speed for Internet connections.
Digital video/versatile disk (DVD)  A digital format primarily used for storing video and movies. However, it can also hold audio and traditional computer data. One side of the disk can hold over 3 gigabytes of data.
Disintermediation  In an e-commerce context, using a Web-based system to skip over sections of the production chain, such as manufacturers selling directly to consumers. The approach can give the manufacturer a higher percentage of the sale price, but risks alienating retailers, resulting in lost sales.
Distribution channel  The layers of distributors in between the manufacturer to the final customer. If a producer can gain control over this means of getting the product to consumers, the producer can prevent new rivals from entering the industry. Improved communication systems offer the possibility of eroding control over some distribution channels.
Diverge  The property of an iterative model where successive computations keep leading to larger values (in magnitude). The model never reaches a stable solution. Generally due to insufficient or incorrect feedback mechanisms.
Documentation  Descriptions of a system, its components, the data, and records of changes made to the system.
Domain name server (DNS)  A computer on the Internet that converts mnemonic names into numeric Internet addresses. The names are easier for humans to remember, but the computers rely on the numeric addresses.
Dot-com  Abbreviation given to the many Internet firms formed in the late 1990s because their Internet names ended with the .com suffix. For a couple of years, having a dot-com name was prestigious and attracted funding. When hundreds of these firms failed in 2000 and 2001, they became known as dot-bombs.
Download  To transfer files from a remote computer to a local computer (usually a personal computer). See also Upload.
Drill down  To use an information system to get increasingly detailed data about a company. In an enterprise information system, the ability to look at overall company data, then select breakdowns by regions, departments, or smaller levels.
Dual-key encryption  A method of encrypting a message that requires two keys- one to encrypt and one to decrypt. One of the keys is a public key that is available to anyone. The other key is private and must never be revealed to other people. RSA is a popular dual-key encryption system. Systems can also be used to authenticate the users.
Dynamic data exchange  An early method of linking data from multiple sources with the Windows operating system. The software packages literally send messages to other software packages, which enables them to combine and update data. See also dynamic integration and Object Linking and Embedding (OLE).
Dynamic integration  A means of linking data from multiple documents. One compound document (or container) can hold data objects created by other software. As the original data is changed, it is automatically updated in the container document. See also Static integration.
EBCDIC  Extended Binary Coded Decimal Interchange Code. A method of numbering characters so they can be processed by machines. Used exclusively by large IBM and compatible computers. See also ASCII.
E-business  Electronic business. The process of conducting any type of business over the Internet. It includes all forms of e-commerce and m-commerce, as well as internal processes and Web services.
E-commerce  Electronic commerce. The process of selling items over the Internet. The most familiar form is business-to consumer, but it includes business-to-business and auction sites like eBay.
Electronic data interchange (EDI)  Exchanging transaction data with entities outside the control of your firm. Private connections can be established directly between two firms. Public networks are also being formed where one provider collects data and routes it to the appropriate client.
E-mail  Electronic mail, or messages that are transmitted from one computer user to another. Networks transfer messages between the computers. Users can send or retrieve messages at any time. The computer holds the message until the recipient checks in.
Encryption  A method of modifying the original information according to some code, so that it can only be read if the user knows the decryption key. It is used to safely transmit data between computers.
End-user development  Managers and workers are to develop their own small systems using database management systems, spreadsheets, and other high-level tools.
Enterprise network  A network that connects multiple subnetworks across an entire firm. Often, the networks use different protocols and different computer types, which complicates transmitting messages.
Enterprise resource planning (ERP)  An integrated computer system running on top of a DBMS. It is designed to collect and organize data from all operations in an organization. Existing systems are strong in accounting, purchasing, and HRM.
Ergonomics  The study of how machines can be made to fit humans better. One of the main conclusions of this research in the computer area is that individuals need to be able to adjust input (and output) devices to their own preferences.
Escrow key  In an encryption system, it is a special key that can be used by government officials to decrypt a secret conversation. The Clipper chip uses escrow keys.
Ethernet  A network communications protocol that specifies how machines will exchange data. It uses a broadcast system in which one machine transmits its message on the communication medium. The other machines listen for messages directed to them.
Ethics  The concept that various elements of society have obligations to the others. In IT, it focuses on the roles of users, developers, and vendors.
Event-driven approach  (1) A user-interface approach where the user controls the sequence or operations and the software responds to these events. Events can range from a simple key press to a voice command. (2) Modern, window-based software does not follow a sequential process. Instead, actions by users generate events. The programs respond to these events and alter data or offer additional choices. Typical events include mouse clicks pointing to items on the screen, keystrokes, changes to values, or transmissions from other systems.
Exception report  Report that is triggered by some event to signify a condition that is unusual and needs to be handled immediately.
Executive information system (EIS)  A type of decision support system that collects, analyzes, and presents data in a format that is easy to use by top executives. To achieve this objective, the EIS is based on a model of the entire company. In most cases the model is presented graphically and the executives retrieve information by pointing to objects on the screen.
Exhaustive testing  Testing every possible combination of inputs to search for errors. Generally not a feasible option, so most computer systems will always contain errors.
Expert system (ES)  A system with the goal of helping a novice achieve the same results as an expert. They can handle ill-structured and missing data. Current expert systems can only be applied to narrowly defined problems. Diagnostic problems are common applications for expert systems.
Expert system shell  A program that provides a way to collect data, enter rules, talk to users, present results, and evaluate the rules for an expert system.
Export  An older method of exchanging data among various software packages. One package exports the data by storing it in a format that can be read by other software. Object Linking and Embedding is a more powerful way to exchange data.
Extensible markup language (XML)  A tag-based notation system that is used to assign names and structure to data. It was mainly designed for transferring data among diverse systems.
External agents  Entities that are outside the direct control of your company. Typical external agents are customers, suppliers, rivals, and governments. Competitive advantages can be found by producing better-quality items or services at a lower cost than your rivals. Also, many firms have strengthened their positions by building closer ties with their suppliers and customers.
External entity  Objects outside the boundary of a system that communicate with the system. Common business examples include suppliers, customers, government agencies, and management.
Extraction, transformation, and transportation (ETT)  The process in data warehouses that involves taking data from existing systems, cleaning it up, and moving it into the data warehouse.
Extreme programming (XP)  A new version of development loosely based on prototyping. Pairs of developers rapidly build and simultaneously test applications. The goal is to build releases and then modify them to meet the changing needs of the users.
Facsimile (Fax)  A combination scanner, transmitter, and receiver that digitizes an image, compresses it, and transmits it over phone lines to another facsimile machine.
Fault-tolerance  The ability of a computer or a system to continue functioning properly even if some of the components fail. Fault-tolerant machines rely on duplication of subsystems with continuous monitoring and automatic maintenance calls.
Feasibility study  A quick examination of the problems, goals, and expected costs of a proposed system. The objective is to determine whether the problem can reasonably be solved with a computer system.
Feedback  Well-designed systems have controls that monitor how well they meet their goal. The information Glossary 593 measuring the goals and providing control to the system is known as feedback.
Fiber-optic cable  A thin glass or plastic cable that is internally reflective. It carries a light wave for extended distances and around corners.
File server  Computer on a network that is used to hold data and program files for users to share. To be effective, it should use a multitasking operating system.
File transfer protocol (FTP)  A standard method of transferring files on the Internet. If you control a computer, you can give other users access to specific files on your computer without having to provide an account and password for every possible user.
Firewall  A small, fast network computer device that examines every packet entering a company. Rules or filters can be created that will reject certain packets that are known to be dangerous to the network.
Five forces model  Michael Porter's model used to search for competitive advantage. The five forces are- rivals, customers, suppliers, potential competitors, and substitute products.
Floating-point operations per second (FLOPS)  The number of mathematical calculations a processor can perform in one second. Typically measured in millions (mega-FLOPS)or billions (giga-FLOPS). Bigger numbers represent faster processors.
Flow chart  An old pictorial method for describing the logic of a computer program. It has largely been replaced by pseudo code.
Font size  An important characteristic of text is its size. Size of type is typically measured in points. For reference, a capital letter in a 72-point font will be approximately 1 inch high.
Forward chaining  In an expert system, the ES traces your rules from the data entry to a recommendation. Forward chaining is used to display questions, perform calculations, and apply rules.
Frame  A related set of information that humans group together. Sometimes groupings can be arbitrary. Used in discussing AI applications and human cognition.
Frame relay  A network communication system that uses variable-length packets. It is useful for high-speed, large bursts of data. It is being used for long-distance network communications.
Franchise  A means of organizing companies. Independent operators pay a franchise fee to use the company name. They receive training and benefit from the name and advertising of the parent company. They purchase supplies from the parent company and follow the franchise rules.
Front-end processor  A simple communications device for large central computers that accepted all of the terminal wires and then assigned each user to an open communications port on the computer. This device decreased the number of physical access ports required on the computer.
Functions  See Methods.
Fuzzy logic  A way of presenting and analyzing logic problems that is designed to handle subjective descriptions (e.g., hot and cold).
General ledger  A collection of accounts that break financial data into specific categories. Common categories include accounts receivable, accounts payable, inventory, and cash.
Geographic information system (GIS)  Designed to identify and display relationships among business data and locations. Used to display geographical relationships. Used to plot delivery routes and create maps.
Gigabyte  Approximately 1 billion bytes of data. Technically, 1,024 to the third power (or 2 to the thirtieth), which is 1,073,741,824. The next highest increment is the terabyte.
Global positioning system (GPS)  A system of 24 satellites created by the U.S. Department of Defense. Receivers will identify a location to within about 50 feet. Used for navigation, tracking vehicles, and plotting delivery routes.
Graphical user interface (GUI)  A system based on a graphics screen instead of simple text. Users perform tasks by clicking a mouse button on or manipulating objects on the screen. For example, copies are made by dragging an item from one location on the screen to another. Pronounced as "gooey."
Group breaks  Reports are often broken into subsections so that data in each section is grouped together by some common feature. For example, a sales report might group items by department, with subtotals for each department.
Group decision support system (GDSS)  A type of groupware that is designed to facilitate meeting and help groups reach a decision. Each participant uses a networked computer to enter ideas and comments. Votes can be recorded and analyzed instantly. Comments and discussion are automatically saved for the further study.
Groupware  Software designed to assist teams of workers. There are four basic types- communication, workflow, meeting, and scheduling. The most common is communication software that supports messages, bulletin boards, and data file transfers and sharing.
Hacker  Primarily used to indicate a person who devotes a great deal of time trying to break into computer systems.
Hardware  The physical equipment used in computing.
High-Definition Television (HDTV)  Transmission of television signals in digital form. It provides clearer reception. It also supports encrypted transmissions so broadcasters can control who receives the images. HDTV also supports compression, so more data (better pictures or more channels) can be transmitted in the same frequency space.
Hot links  See Dynamic integration.
Hot site  A facility that can be leased from a disaster backup specialist. A hot site contains all the power, telecommunication facilities, and computers necessary to run a company. In the event of a disaster, a company collects its backup data tapes, notifies workers, and moves operations to the hot site.
Hub  A network device used to connect several computers to a network. Commonly used in a twisted-pair LAN. Runs from each computer's NIC to the hub. The hub is often connected to a router.
Hypertext markup language (HTML)  The standard formatting system used to display pages on the Internet. Special tags (commands inside angle braces) provide formatting capabilities. Several software packages automatically store text in this format, so users do not have to memorize the tags.
Icon  A small picture on a computer screen that is used to represent some object or indicate a command. A classic example is the trash can used to delete files on the Apple Macintosh.
Image  A graphic representation that can be described by its resolution and the number of colors. They can be stored as bitmapped or vector images.
Import  An older method of exchanging data among various software packages. Most software (e.g.Management system) can export or store data in a text file format. Another software package (e.g.Import or retrieve this data. Object Linking and Embedding is a more powerful way to exchange data.
Inference engine  Within an expert system, the inference engine applies new observations to the knowledge base and analyzes the rules to reach a conclusion.
Information  Data that has been processed, organized, and integrated to provide insight. The distinction between data and information is that information carries meaning and is used to make decisions.
Information center  A MIS group responsible for supporting end users. It typically provides a help desk to answer questions, programmers who provide access to corporate databases, training classes, and network support people to install and maintain networks.
Information system  A collection of hardware, software, data, and people designed to collect, process, and distribute data throughout an organization.
Information technology  The hardware and software used to create an information system. Sometimes used as an abbreviation for management information systems.
Information threats  There are two classes of threats to information- (1) physical, in the form of disasters; and (2) logical, which consists of unauthorized disclosure, unauthorized modification, and unauthorized withholding of data. The primary source of danger lies with insiders- employees, ex-employees, partners, or consultants.
Information warfare  The use of information in a conflict setting. It includes protecting your own information, providing misinformation to the enemy, and monitoring and disrupting the enemy's information.
Inheritance  Creation or derivation of classes of objects from other object classes. Each derived class inherits the attributes and methods of the prior class. For example, a savings account object can be derived from an account object.The savings account object will automatically have the same attributes and methods. Attributes and methods specific to the savings account can be added.
Initial public offering (IPO)  The step when firms sell stock to the public. A method of raising additional funds and a major step for most startup firms.
Input devices  People do not deal very well with binary data, so all data forms must be converted into binary form for the computer. Input devices-for example, keyboards, microphones, and bar-code readers-make the conversion.
Input-Process-Output  A shorthand description of a subsystem. Each subsystem receives inputs and performs some process. The output is passed to another subsystem.
Integrated data  The practice of combining data from many sources to make a decision. Data can come from different department throughout the business, and it can come in many different forms. Networks, groupware, and products that support dynamic linking are all useful tools to integrate data to make better decisions.
Integrated Services Digital Network (ISDN)  A set of services, and a transmission and control system, offered by telephone companies. It uses complete digital transmission of signals to improve transmission speed and quality.
Intellectual property  As defined by copyright laws, the concept that property like music, books, software, and movies can be protected. The laws clearly define the owners of the property and specify that the owners can establish any type of copy protections they desire.
Internet  A collection of computers loosely connected to exchange information worldwide. Owners of the computers make files and information available to other users. Common tools on the Internet include e-mail, ftp, telnet, and the World Wide Web.
Internet service provider (ISP)  A private company that provides connections to the Internet. Individuals pay a fee to Glossary 595the ISP. The ISP pays a fee to a higher-level provider (e.g. NSP) to pass all communications onto the Internet.
Intranet  A network within an organization that utilizes standard Internet protocols and services. Essentially, this includes websites that are accessible only for internal use.
Intrusion detection system (IDS)  A combination of hardware and software that monitors packets and operations on the network and computers. It watches for suspicious patterns that might indicate an attack.
Iterative solution  Building a model and evaluating it until the parameter values converge to a fixed solution. Sometimes an iterative model will diverge and never reach an acceptable solution. See also Circular reference.
Joint application design (JAD)  A method to reduce design time by putting everyone in development sessions until the system is designed. Users, managers, and systems analysts participate in a series of intense meetings to design the inputs (data and screens), and outputs (reports) needed by the new system.
Just-in-time (JIT) inventory  A production system that relies on suppliers delivering components just as they are needed in production, instead of relying on inventory stocks. JIT requires close communication between manufacturers and suppliers.
Kerberos  A security system created at MIT that enables systems to have a single sign-on. Users log into the Kerberos server and other systems can validate the user's identity from that server; much simpler than requiring users to log-in multiple times. Named after the hound that guards the gates of Hades (spelled Cerberus in Latin).
Kilobyte  Approximately one thousand bytes of data. Technically it is 2 to the tenth, or 1,024.
Knowledge  A higher level of understanding, including rules, patterns, and decisions. Knowledge-based systems are built to automatically analyze data, identify patterns, and recommend decisions.
Knowledge base  Within an expert system, the knowledge base consists of basic data and a set of rules.
Knowledge engineer  A person who helps build an expert system by organizing the data, devising the rules, and entering the criteria into the expert system shell; trained to deal with experts to derive the rules needed to create an expert system. The engineer also converts the data and rules into the format needed by the expert system.
Knowledge Management (KM)  A system that stores information in the context of a set of decisions. It contains 596 Glossary cross-references and search methods to make it easy for workers to understand how and why decisions were made.
Legacy systems  Information systems that were created over several years and are now crucial to operating the company.They probably use older technology, and the software is difficult to modify. However, replacing them is difficult and likely to interfere with day-to-day operations. Any changes or new systems must be able to work with the older components.
Limited liability company  A legal variation of organizing a company. It protects the owners with the same separation of funds offered to corporations, but because it does not allow it to issue stock, the record keeping is somewhat easier.
Local area network (LAN)  A collection of personal computers within a small geographical area, connected by a network. All of the components are owned or controlled by one company.
Magnetic hard drives  Magnetic hard drives (or disk drives) consist of rigid platters that store data with magnetic particles. Data is accessed by spinning the platters and moving a drive head across the platters to access various tracks.
Magnetic ink character recognition (MICR)  A special typeface printed with ink containing magnetic particles. It can be read rapidly and reliably by computers. Banks are the primary users of MICR. Checks are imprinted with MICR routing numbers. MICR readers are more accurate than straight OCR because they pick up a stronger signal from magnetic particles in the ink.
Mail filters  Programs that automatically read e-mail and sort the messages according to whatever criteria the manager prefers. Junk mail can be discarded automatically.
Management information system (MIS)  Consists of five related components- hardware, software, people, procedures, and databases. The goal of management information systems is to enable managers to make better decisions by providing quality information.
Manufacturing Resource Planning (MRP II)  An integrated approach to manufacturing. Beginning with the desired production levels, we work backward to determine the processing time, materials, and labor needed at each step. These results generate schedules and inventory needs. Sometimes known as a demand-pull system.
Mass customization  The ability to modify the production line often enough to produce more variations of the main product. The goal is to cover virtually all of the niche markets.
Materials requirements planning (MRP)  An early production system, where at each stage of production, we evaluate the usage of materials to determine the optimal inventory levels.
Mathematical model  A model that is defined by mathematical equations. This format is easy to use for forecasts and for simulation analyses on the computer. Be careful not to confuse precision with accuracy. A model might forecast some value with great precision (e.g., 15.9371), but the accuracy could be quite less (e.g., actual values between 12 and 18).
Media  For the means of transmissions, connecting computers in a network. Common methods include twisted pair and coaxial cable; fiber-optic lines; and radio, micro, and infrared waves.
Megabyte  Loosely, 1 million bytes of data. Technically, it is 1,048,576 bytes of data, which are 2 raised to the 20th power.
Megaflops  Millions of floating-point operations per second. A measure of the processor speed, it counts the number of common arithmetical operations that can be performed in one second.
Megahertz  One million cycles per second, a measure of the clock chip in a computer, which establishes how fast a processor can operate.
Menu tree  A graphical depiction of the menu choices available to users in a system.
Metadata  Describes the source data, and the transformation and integration steps, and defines the way the database or data warehouse is organized.
Methods  Descriptions of actions that an object can perform. For example, an employee object could be hired, promoted, or released. Each of these functions would necessitate changes in the employee attributes and in other objects. The methods carry out these changes.
Microsecond  One-millionth of a second. Few computer components are measured in microseconds, but some electrical devices and controllers operate in that range. One microsecond compared to one second is the same as comparing one second to 11.6 days.
Million instructions per second (MIPS)  A measure of computer processor speed. Higher numbers represent a faster processor. However, different brands of processors use different instruction sets, so numbers are not always comparable.
Millisecond  One-thousandth of a second. Disk drives and some other input and output devices perform operations measured in milliseconds. One millisecond compared to one second is the same as comparing 1 second to 16.7 minutes.
Mirror drive  A backup system where data is automatically written to a second disk drive. If the primary drive fails, operations can be switched instantaneously to the mirror drive.
Model  A simplified, abstract representation of some real world system. Some models can be written as mathematical equations or graphs, others are subjective descriptions. Models help managers visualize physical objects and business processes. Information systems help you build models, evaluate them, and organize and display the output.
Modem  Modulator-demodulator. A device that converts computer signals into sounds that can be transmitted (and received) across phone lines.
Morphing  Digital conversion of one image into another. The term is an abbreviation of metamorphosis. True morphing is done with digital video sequences, where the computer modifies each frame until the image converts to a new form.
Multimedia  The combination of the four basic data types- text, sound, video, and images (animation). In its broadest definition, multimedia encompasses virtually any combination of data types. Today, it typically refers to the use of sound, text, and video clips in digitized form that are controlled by the computer user.
Multitasking  A feature of operating systems that enables you to run more than one task or application at the same time.Technically, they do not run at exactly the same time. The processor divides its time and works on several tasks at once.
Musical Instrument Data Interchange (MIDI)  A collection of standards that define how musical instruments communicate with each other. Sounds are stored by musical notation and re-created by synthesizers that play the notes.
Nanosecond  One-billionth of a second. Computer processors and memory chips operate at times measured in nanoseconds. One nanosecond compared to 1 second is the same as comparing 1 second to 31.7 years.
Natural language  A human language used for communication with other humans, as opposed to a computer programming language or some other artificial language created for limited communication.
Network interface card (NIC)  The communication card that plugs into a computer and attaches to the network communication medium. It translates computer commands into network messages and server commands.
Network operating system (NOS)  A special operating system installed on a file server, with portions loaded to the client machines. It enables the machines to communicate and share files.
Network service provider (NSP)  A high-level Internet service provider offering connections to ISP's. The NSP leases high-speed, high-capacity lines to handle the communication traffic from hundreds of ISP's.
Neural network  A collection of artificial neurons loosely designed to mimic the way the human brain operates; especially useful for tasks that involve pattern recognition.
Neuron  The fundamental cell of human brains and nerves. Each of these cells is relatively simple, but there are approximately 100 million of them.
Newsgroups  A set of electronic bulletin boards available on the Internet. Postings are continuously circulated around the network as people add comments.
Normalization  A set of rules for creating tables in a relational database. The primary rules are that there can be no repeating elements and every non key column must depend on the whole key and nothing but the key. Roughly, it means that each table should refer to only one object or concept.
Numbers  One of the basic data types, similar to text on input and output. Attributes include precision and a scaling factor that defines the true size or dimension of the number.
Object  A software description of some entity. It consists of attributes that describe the object, and functions (or methods) that describe the actions that can be taken by the object. Objects are generally related to other objects through an object hierarchy.
Object hierarchy  Objects are defined from other base objects. The new objects inherit the properties and functions of the prior objects.
Object Linking and Embedding (OLE)  A standard created by Microsoft for its Windows operating system to create compound documents and dynamically link data objects from multiple software packages. You begin with a compound document or container that holds data from other software packages. These data objects can be edited directly (embedded). Most OLE software also supports dynamic linking.
Object orientation  An approach to systems and programming that classifies data as various objects. Objects have attributes or properties that can be set by the programmer or by users. Objects also have methods or functions that define the actions they can take. Objects can be defined from other objects, so most are derived from the four basic data types.
Object-oriented DBMS  A database system specifically created to hold custom objects. Generally supports developer defined data types and hierarchical relationships.
Object-oriented design  The ultimate goal of the object-oriented approach is to build a set of reusable objects and procedures. The idea is that eventually, it should be possible to create new systems or modify old ones simply by plugging in a new module or modifying an existing object.
One-to-many relationship  Some object or task that can be repeated. For instance, a customer can place many orders. Database normalization, we search for one-to-many relationships and split them into two tables.
Online analytical processing (OLAP)  A computer system designed to help managers retrieve and analyze data. The systems are optimized to rapidly integrate and retrieve data. The storage system is generally incompatible with transaction processing, so it is stored in a data warehouse.
Online transaction processing (OLTP)  A computer system designed to handle daily transactions. It is optimized to record and protect multiple transactions. Because it is generally not compatible with managerial retrieval of data, data is extracted from these systems into a data warehouse.
Open operating system  An operating system that is supposed to be vendor neutral. It should run on hardware from several different vendors. When a buyer upgrades to a new machine, the operating system and software should function the same as before.
Open system  An open system learns by altering itself as the environment changes.
Operating system  A basic collection of software that handles jobs common to all users and programmers. It is responsible for connecting the hardware devices, such as terminals, disk drives, and printers. It also provides the environment for other software, as well as the user interface that affects how people use the machine.
Operations level  Day-to-day operations and decisions. In a manufacturing firm, machine settings, worker schedules, and maintenance requirements would represent management decisions at the operations level. Information systems are used at this level to collect data and perform well-defined computations.
Optical character recognition (OCR)  The ability to convert images of characters (bitmaps) into computer text that can be stored, searched, and edited. Software examines a picture and looks for text. The software checks each line, deciphers one character at a time, and stores the result as text.
Optimization  The use of models to search for the best solutions- minimizing costs, improving efficiency, or increasing profits.
Output devices  Data stored in binary form on the computer must be converted to a format people understand. Output devices-for example, display screens, printers, and synthesizers-make the conversion.
Outsourcing  The act of transferring ownership or management of MIS resources (hardware, software, and personnel) to an outside MIS specialist.
Packets  Network messages are split into packets for transmission. Each packet contains a destination and source address as well as a portion of the message.
Packet switching network  A communications protocol in which each message is placed into smaller packets. These packets contain a destination and source address. The packets are switched (or routed) to the appropriate computer. With high-speed switches, this protocol offers speeds in excess of 150 megabits per second.
Page footer  Data that is placed at the bottom of each page in a report. Common items include page totals and page numbers.
Page header  Data that is placed at the top of every page in a report. Common items include the report title, date, and column labels.
Parallel processing  Using several processors in the same computer. Each processor can be assigned different tasks, or jobs can be split into separate pieces and given to each processor. There are a few massively parallel machines that utilize several thousand processors.
Parameter  Variables in a model that can be controlled or set by managers. They are used to examine different situations or to tailor the model to fit a specific problem.
Patent  Legal protection for products (and sometimes business processes). It grants the owner sole right to sell or create modifications of the product for 20 years. No one can create the same product unless approved by the patent owner.
Peer-to-peer communication  A method of sharing data and information directly with colleagues and peers, instead of transferring data through a shared central server.
Peer-to-peer network  A network configuration in which each machine is considered to be an equal. Messages and data are shared directly between individual computers. Each machine continuously operates as both a client and a server.
Personal digital assistant (PDA)  A small portable, handheld computer designed primarily to handle contacts, schedules, e-mail, and short notes. Some models have more advanced features to support documents, spreadsheets, photos, and music. A few have wireless connections, others have to be synchronized with desktops to transfer e-mail and update schedules.
Photo-CD  A standardized system created by Kodak to convert photographs to digital (bitmap) form and store them on optical disks.
Pivot table  A tool within Microsoft Excel used to extract and organize data. It enables users to examine aggregated data and quickly see the accompanying detail.
Pixel  Picture element, or a single dot on an image or video screen.
Point-of-sale (POS) system  A means of collecting data immediately when items are sold. Cash registers are actually data terminals that look up prices and instantly transmit sales data to a central computer.
Polymorphism  In an object design, different objects can have methods that have the same name but operate slightly differently. For example, a checking account object and a savings account object could each have a method called pay interest. The checking account might pay interest monthly, whereas the savings account pays it quarterly.
Portable document format (PDF)  A file format often used on the Internet. It can display documents with detailed precision, including special fonts and shading. Defined by Adobe, readers are freely available for many machines. Special software must be purchased to create the files.
Precision (numeric)  In computers, numeric precision represents the number of digits stored to the right of the decimal point. So, 10.1234 is more precise than 10.However, it is not necessarily more accurate. The original value might not have been measured beyond two digits.
Prediction  Model parameters can be estimated from prior data. Sample data is used to forecast future changes based on the model.
Pretty good privacy (PGP)  A dual-key encryption system based on the Diffie-Hellman approach similar to RSA. Created by Philip Zimmermann and commonly used to encrypt e-mail. Free copies for noncommercial use are still available from MIT.
Primary key  A column or set of columns that contains data to uniquely identify each row in a relational database table. For example, each customer must have a unique identifier, possibly a phone number or an internally generated customer number.
Privacy  (1) The concept that people should be able to go about their lives without constant surveillance, that personal information about people should not be shared without their permission. (2) Collecting personal data only when you have a legitimate use for it, allowing customers to correct and remove personal data. Protecting confidential data so that it is not released to anyone. Giving customers the option so you do not sell or lease their personal data.
Private key  In a dual-key encryption system, the key that is protected by the owner and never revealed. It is generally a very large number.
Problem boundary  The line that identifies the primary components of the system that are creating a specific problem. Subsystems inside the boundary can be modified to solve the problem or enhance the system. Subsystems outside the boundary cannot be altered at this time.
Procedures  Instructions that help people use the systems. They include items such as user manuals, documentation, and procedures to ensure that backups are made regularly.
Process  An activity that is part of a data flow diagram. Systems can be built to process goods or to process data. Most information system work focuses on processes that alter data.
Process control  The use of computers to monitor and control the production machines and robots. Production lines generally use many different machines, each requiring several adjustments or settings. Computer control simplifies and speeds the setup.
Process control system  A computerized system that monitors and controls a production line. Some systems are completely linked so that a central computer can set up machines on an entire assembly line.
Process innovation  Evaluating the entire firm to improve individual processes, and to search for integrated solutions that will reduce costs, improve quality, or boost sales to gain a competitive advantage. See also Re-engineering.
Processor  The heart of a computer. It carries out the instructions of the operating system and the application programs.
Product differentiation  The ability to make your products appear different from those of your rivals, thus attracting more customers. Information systems have been used to alter products and provide new services.
Properties  See Attributes.
Protocols  A set of definitions and standards that establish the communication links on a network. Networks are often classified by their choice of protocol. Common protocols include Ethernet, Token Ring, and TCP/IP.
Prototyping  An iterative system design technique that takes advantage of high-level tools to rapidly create working systems. The main objective of prototyping is to create a working version of the system as quickly as possible, even if some components are not included in the early versions.
Pseudocode  A loosely structured method to describe the logic of a program or outline a system. It uses basic programming techniques but ignores issues of syntax and relies on verbal descriptions.
Public key  In a dual-key encryption system, the key that is given to the public. Each person wishing to use dual-key encryption must have a different public key. The key works only in tandem with the user's private key.
Pure Internet plays  Dot-com firms that have no direct tie to traditional business. Firms that make all their revenue from Internet sales or other Internet firms. A popular concept in 1999, but most pure Internet firms failed in 2000 and 2001.
Query by example (QBE)  A visual method of examining data stored in a relational database. You ask questions and examine the data by pointing to tables on the screen and filling in templates.
Query system  A method of retrieving data in a DBMS. It generally uses a formal process to pose the questions- (1) what columns should be displayed? (2) What conditions are given? (3) what tables are involved? And (4) how are the tables connected? See Query by example and SQL.
Random access memory (RAM)  High-speed memory chips that hold data for immediate processing. On most computers, data held in RAM is lost when the power is removed, so data must be moved to secondary storage.
Rapid application development (RAD)  The goal of building a system much faster than with traditional SDLC methods. Using powerful tools (database management system, high-level languages, graphical toolkits, and objects), highly trained programmers can build systems in a matter of weeks or months. Using workgroups, communication networks, and CASE tools, small teams can speed up the development and design steps.
Read Only Memory (ROM)  A type of memory on which data can be stored only one time. It can be read as often as needed but cannot be changed. ROM keeps its data when power is removed, so it is used to hold certain core programs and system data that is rarely changed.
Reduced instruction set computer (RISC)  When designing a RISC processor, the manufacturer deliberately limits the number of circuits and instructions on the chip. The goal is to create a processor that performs a few simple tasks very fast. More complex problems are solved in software. Because RISC processors require fewer circuits, they are easier to produce.
Redundant array of independent disks (RAID)  A system consisting of several smaller drives instead of one large one.Large files are split into pieces stored on several different physical drives. The data pieces can be duplicated and stored in more than one location for backup. RAID systems also provide faster access to the data, because each of the drives can be searching through their part of the file at the same time.
Re-engineering  A complete reorganization of a company. Beginning from scratch, you identify goals, along with the most efficient means of attaining those goals, and create new processes that change the company to meet the new goals. The term reengineering and its current usage were made popular in 1990 by management consultants James Champy and Michael Hammer.
Relational database  A database in which all data is stored in flat tables that meet the normalization rules. Tables are logically connected by matching columns of data. System data, such as access rights, descriptions, and data definitions are also stored in tables.
Repetitive stress injury (RSI)  An injury that occurs from repeating a stressful action. For instance, several people have complained that constant typing damages their wrists. Ergonomic design, adjusting your workspace, and taking breaks are common recommendations to avoid repetitive stress.
Report  A printed summary or screen display that is produced on a regular basis by a database management system. The main sections of a report are- report header, page header, group/break header, detail, group/break footer, page footer, and report footer.
Request for proposal (RFP)  A list of specifications and questions sent to vendors asking them to propose (sell) a product that might fill those needs.
Resolution  The number of dots or pixels displayed per inch of horizontal or vertical space. Input and output devices, as well as images and video, are measured by their resolution. Higher values of dots-per-inch yield more detailed images.
Reverse engineering  The process of taking older software and rewriting it to modernize it and make it easier to modify and enhance. Reverse engineering tools consist of software that reads the program code from the original software and converts it to a form that is easier to modify.
Rivals  Any group of firms that are competing for customers and sales. Similar to competitors, but "competition" carries an economic definition involving many firms. Even an industry with two firms can experience rivalry.
Rivest-Shamir-Adelman (RSA)  Three mathematicians who developed and patented a dual-key encryption system. The term often refers to the encryption technique. It is based on the computational difficulty of factoring very large numbers into their prime components.
Rocket scientists  Mathematically trained financial analysts who build complex mathematical models of the stock market and help create and price new securities.
Router  A communication device that connects subnet works together. Local messages remain within each subnetwork. Messages between subnetworks are sent to the proper location through the router.
Row  A horizontal element that contains all of the data to describe an entity or object in a relational database or spreadsheet.
Rules  A set of conditions that describe a problem or a potential response. Generally expressed as "If . . .conditions. Used by expert systems to analyze new problems and suggest alternatives.
Sampler  An input device that reads electrical signals from a microphone and stores the sound as a collection of numbers. It measures the frequency and amplitude of the sound waves thousands of times per second.
Scalability  The ability to buy a faster computer as needed and transfer all software and data without modification. True scalability enables users to buy a smaller computer today and upgrade later without incurring huge conversion costs.
Scrolling region  On a data entry form, a subform or section that is designed to collect multiple rows of data. Much like a spreadsheet, the user can move back and forth to alter or examine prior entries.
Secondary storage  Data storage devices that hold data even if they lose power. Typically cheaper than RAM, but slower. Disk drives are common secondary storage devices.
Serifs  The small lines, curlicues, and ornamentation on many typefaces. They generally make it easier for people to read words and sentences on printed output. Sans serif typefaces have more white space between characters and are often used for signs and displays that must be read from a longer distance.
Server farm  A collection of dozens or hundreds of smaller servers. Software allocates tasks to whichever server is the least busy. This approach to scalability is fault-tolerant and easy to expand, but can be difficult to manage.
SharePoint  Microsoft's Web-based tool for teamwork. It supports file sharing, version control, discussion groups, and surveys.
Sign-off  In a systems development life-cycle approach, the approval those managers must give to forms, reports, and computations at various stages of the development. This approval is given when they sign the appropriate documents.
Simple object access protocol (SOAP)  A standard, easy to- implement method of exchanging information and messages among different computers on the Internet. A protocol that works with XML to support Web-based services.
Simulation  Models are used to examine what might happen if we decide to make changes to the process, to see how the system will react to external events, or to examine relationships in more detail.
Social legitimacy  At one time, mainstream organizations were identified by the quality of their presentation and their image. Large firms spend millions of dollars on graphic artists, professional designers, and professional printing. The decreasing cost of computers enables even small organizations to create an image that is hard to distinguish from large organizations.
Software  A collection of computer programs that are algorithms or logical statements that control the hardware.
Software maintenance  The act of fixing problems, altering reports, or extending an existing system to improve it. It refers to changes in the software, not to hardware tasks such as cleaning printers.
Software piracy  The act of copying software without paying the copyright owner. With few exceptions (e.g.backup), copying software is illegal. Companies and individuals who are caught have to pay thousands of dollars in penalties and risk going to jail. It is commonly accepted that piracy takes money away from the development of improved software.
Software suites  Collections of software packages that are designed to operate together. Theoretically, data from each package can be easily shared with data from the others. So word processors can incorporate graphics, and spreadsheets can retrieve data from the database management system. Suites are often sold at a substantial discount compared to buying each package separately.
Sound  One of the basic data types. There are two methods to describe sound- samples or MIDI. Digitized (sampled) sound is based on a specified sampling and playback rate, and fits into frequency and amplitude (volume) ranges.
Speech recognition  The ability of a computer to capture spoken words, convert them into text, and then take some action based on the command.
SQL  A structured query language supported by most major database management systems. The most common command is of the form- SELECT column list FROM table list JOIN how tables are related WHERE condition ORDER BY columns.
Standard operating procedures  A set of procedures that define how employees and managers should deal with certain situations.
Standards  An agreement that specifies certain technical definitions. Standards can be established by committees or evolve over time through market pressures. As technology changes, new standards are created.
Static HTML  Simple HTML pages that are changed only by humans, so they are rarely changed. Generally used only for the pre-purchase information stage of e-commerce.
Static integration  A means of combining data from two documents. A copy of the original is placed into the new document. Because it is static, changes made to the original document are not automatically updated. See also Dynamic integration.
Statistical quality control (SQC)  The statistical analysis of measurement data to improve quality. Several statistical calculations and graphs are used to determine whether fluctuations are purely random or represent major changes that need to be corrected.
Stock options  A right to purchase a specific stock at a given price. Often granted to workers and managers in startup companies. If the company grows rapidly, its stock price should increase. The option owner can cash in the options and receive the difference between the current price and the option price.
Strategic decisions  Decisions that involve changing the overall structure of the firm. They are long-term decisions and are unstructured. They represent an attempt to gain a competitive advantage over your rivals. They are usually difficult and risky decisions. MIS support for strategic decisions typically consists of gathering, analyzing, and presenting data on rivals, customers, and suppliers.
Structured decisions  Decisions that can be defined by a set of rules or procedures. They can be highly detailed, but they are defined without resorting to vague definitions.
Structured walkthrough  A review process in which the objective is to reveal problems, inaccuracies, ambiguities, and omissions in the systems design before the program code is finalized. The users are presented with a prototype or mockup of the proposed system.
Subchapter S corporation  A legal variation of a corporation that can be chosen by the owners. The IRS and some states impose limits on the type of company that can elect this option. It avoids the problem of double taxation by passing income and losses directly to the owners' personal income tax statements.
Supply chain management (SCM)  Organizing the entire supply process including vendor selection, parts management, ordering, payment, and quality control.
Switch  A network device used to connect machines. Unlike a router, a switch creates a virtual circuit that is used by a single machine at a time.
Switching costs  The costs incurred in creating a similar information system when a customer switches to a rival firm. Information technology creates switching costs because customers would have to convert data, re-create reports, and retrain users.
Synthesizer  An electronic device to convert electrical signals into sound. One basic technique is FM synthesis, which generates and combines fixed waves to achieve the desired sound. A newer method combines short digitized samples of various instruments with waveforms to create more realistic sounds.
Sysop  System operator. Person in charge of an electronic bulletin board who organizes files and controls access and privileges.
System  A collection of interrelated objects that work toward some goal.
Systems analysis and design  A refinement of the scientific method that is used to analyze and build information systems.
Systems analyst  A common job in MIS. The analyst is responsible for designing new systems. Analysts must understand the business application and be able to communicate with users. Analysts must also understand technical specifications and programming details.
Systems development life cycle (SDLC)  A formal method of designing and building information systems. There are five basic phases- (1) feasibility and planning, (2) systems analysis, (3) systems design, (4) implementation, and (5) maintenance and review.
T1, T3  An older communication link provided by phone companies. Used to carry digitized analog signals, it is being replaced with ISDN links. T1 refers to a group of 24 voice grade lines and can carry 1.544 megabits per second (Mbps). A T2 trunk line is equivalent to 96 voice circuits providing6.312 Mbps. T3 provides 44.139,264 Mbps. Services can be leased at any of these levels, where greater bandwidth carries higher costs.
Table  A method of storing data in a relational database. Tables contain data for one entity or object. The columns represent attributes, and data for each item is stored in a single row. Each table must have a primary key.
Tactical decisions  Tactical decisions typically involve timeframes of less than a year. They usually result in making relatively major changes to operations but staying within the existing structure of the organization. MIS support consists of databases, networks, integration, decision support systems, and expert systems.
Telnet  A method supported on the Internet that enables users of one computer to log on to a different computer. Once logged on to the new system, the user is treated as any other user on the system.
Terabyte  Approximately 1 trillion bytes of data. Technically, it is 2 to the 40th power.
Text  The simplest of the four basic data types, it also includes numbers. In its most basic form, text is made up of individual characters, which are stored in the computer as numbers. More sophisticated text is described by its typeface, font size, color, and orientation (rotation).
Thin client  Simpler hardware than a full-blown personal computer, with minimal software. It is generally used to display applications running on the server and accept input from the user.
Token Ring  A communications protocol that describes when each machine can send messages. A machine can only transmit when it receives a special message called a token. When the message is finished or a time limit is reached, the token is passed to the next machine.
Top-down development  An approach to designing and building systems that begins with an analysis of the entire company and works down to increasing detail. A complete top-down approach is usually impossible because it takes too long to analyze everything. See also Bottom-up development.
Total cost of ownership (TCO)  The cost of purchasing and running a client computer (personal computer). A highly subjective number, it typically includes the hardware cost, the software license fees, maintenance costs, and training costs.
Total quality management (TQM)  A management doctrine that states that quality must be built into every process and item. Every step and each person must be dedicated to producing quality products and services.
Transaction-processing system  A system that records and collects data related to exchanges between two parties. This data forms the foundation for all other information system capabilities. MIS support typically consists of databases, communication networks, and security controls.
Transborder data flow (TBDF)  The transfer of data across national boundaries. Some countries place restrictions on the transfer of data, especially data that relates to citizens (and of course, data related to "national security"). Some people have discussed taxing the flow of data.
Triggered rule  In an expert system, if a rule is used in an application, it is said to have been triggered or fired.
Trojan horse  A special program that hides inside another program. Eventually, when the main program is run, the Trojan horse program might delete files, display a message, or copy data to an external computer.
True color  Humans can distinguish about 16 million colors. Devices that can display that many colors are said to display true color. It requires the device to use 3 bytes (24 bits) for each pixel.
Turing test  A test proposed by Alan Turing in which a machine would be judged "intelligent" if the software could use conversation to fool a human into thinking it was talking with a person instead of a machine.
Twisted-pair cable  Common dual-line wire. Often packaged as three or four pairs of wires. The cable can be run for only a limited distance, and the signal is subject to interference.
Typeface  A defined way to draw a set of text characters. Several thousand typefaces have been created to meet different artistic and communication needs. A common characterization is serif and sans serif typefaces.
Unicode  An international standard that defines character sets for every modern (living) language and many extinct languages (e.g., Latin).
Un-interruptable power supply (UPS)  A large battery and special circuitry that provides a buffer between the computer and the power supply. It protects the computer from spikes and brownouts.
Universal description discovery, and integration (UDDI)  A public Web-based directory system designed to enable computers to find and use Web services offered by other companies. For example, someday your computer could automatically find all companies that can use current exchange rates to convert prices.
UNIX  A popular operating system created by Bell Labs. It is designed to operate the same on hardware from several different vendors. Unfortunately, there are several varieties of UNIX, and software that operates on one version often must be modified to function on other machines.
Unstable model  A model that cannot be solved for a single solution. The solution might continually diverge, or it could oscillate between several alternatives. Generally due to insufficient or incorrect feedback mechanisms.
Upload  To transfer files from a local computer (usually a personal computer) to a distant computer. See also Download.
Usenet  See News groups.
User resistance  People often resist change. Implementation of a new system highlights this resistance. Managers and developers must prepare for this resistance and encourage users to change. Education and training are common techniques.
Value chain  A description of the many steps involved in creating a product or service. Each step adds value to the product or service. Managers need to evaluate the chain to find opportunities to expand the firm and gain more sales and profits.
Vector image  A stored collection of mathematical equations, representing lines, circles, and points. These equations can be rescaled to fit any output device or to any desired size. Users deal with the base objects, not the mathematical definitions.
Venture capital  Money offered by specialized firms to startup companies. Banks rarely give money to startups, so venture capitalists finance risky ventures in the hope of high profits when the company goes public. Many strings can be attached to the money-including a loss of control.
Version control  Software that tracks changes made to other documents. Often used in software development to enable developers to go back to prior version.
Video  One of the basic data types. Video combines the attributes of images and sound. An important attribute is the frames-per-second definition. U.S. 30 frames-per-second, movie films run at 24 frames-per second. Digitizing video requires capturing and playing back the frames at the appropriate speed.
View  A stored query. If you have a complex query that you have to run every week, you (or a database specialist) could create the query and save it as a view with its own name. It is then treated much like a simple table.
Virtual mall  A collection of Web-based merchants who join together for marketing purposes. Generally they share a common Web host and the same commerce server software. By sharing costs, they can survive without a huge amount of sales.
Virtual private network (VPN)  Software installed on a company network and on each client that automatically encrypts all communications between the two; useful when workers travel or need to reach the company servers from home using the Internet.
Virtual reality (VR)  Virtual reality describes computer displays and techniques that are designed to provide a realistic image to user senses, including three-dimensional video, three dimensional sound, and sensors that detect user movement that is translated to on-screen action.
Virus  A malicious program that hides inside another program. As the main program runs, the virus copies itself into other programs. At some point, the virus displays a message, shuts down the machine, or deletes all of the files.
Visual BASIC  A modern variation of the BASIC programming language created by Microsoft for application programming in Windows. A variation resides inside many of the Microsoft applications, enabling programmers to manipulate and exchange data among the database, spreadsheet, and word processor.
Visual table of contents  A graphical design method that shows how modules of a system are related. Versions of the technique are also used to display menu trees.
Voice mail  A messaging system similar to telephone answering machines but with additional features like message store and forward. You can use your computer to send messages to co-workers. There are tools that will read e-mail and fax messages over the phone, so managers can stay in touch while they are away from the computer.
Voice over Internet protocol (VoIP)  Connecting telephones to the network and using the Internet to transfer phone conversations-instead of traditional phone lines.
Voice recognition  The ability of a computer to capture spoken words and convert them into text.
Webmaster  Specialized IS worker who is responsible for creating, maintaining, and revising a company's World Wide Web site. Webmasters use technical and artistic skills to create sites that attract browsers.
Wide area network (WAN)  A network that is spread across a larger geographic area. In most cases, parts of the network are outside the control of a single firm. Long-distance connections often use public carriers.
Window  A portion of the computer screen. You can move each window or change its size. Windows enable you to display and use several applications on the screen at one time.
Wisdom  A level above knowledge. Wisdom represents intelligence, or the ability to analyze, learn, adapt to changing conditions, and create knowledge.
Workflow software  A type of GroupWare that is designed to automate forms handling and the flow of data in a company. Forms and reports are automatically routed to a list of users on the network. When each person adds comments or makes changes, it is routed to the next process.
Workstations  Computers attached to a network, designed for individual use. Typically, personal computers.
World Wide Web (WWW)  A first attempt to set up an international database of information. Web browsers display graphical pages of information, including pictures. Hypertext connections enable you to get related information by clicking highlighted words.
WORM (Write Once, Read Many) disk  Similar to a CD-ROM, but it is easier to store data. Once data is written on the disk, it cannot be changed. Early WORM drives were superseded by lower-cost drives that can store data in standard CD-ROM format.
WYSIWYG  What you see is what you get. With a true WYSIWYG system, documents will look exactly the same on the screen as they do when printed. In addition to format, it means that the printer must have the same typefaces as the video display. Color printers use a system to match the colors on the monitor.
zShops offers small companies a relatively inexpensive e-commerce solution with little or no fixed costs. Useful for small firms, the system provides marketing, visibility, and a payment mechanism.