iCheck Microsoft Office 2003 Introductory

These articles further explore computer safety, ethics, and many other topics covered in the Technology Handbook found in the student edition.

Boolean Logic (p. H38)

Introduction Learn about Boolean logic.

Directions Read the information below and apply what you learn to answer the questions. Check your work carefully, and click Check Answers.

Refining a Keyword Search

When you use a search engine, you want to find Web pages that contain useful, or relevant, information. If you use only one keyword to search the Web, you may find that you get a very high number of results, most of which are irrelevant. For example, if you want to find information about tennis lessons, a general keyword such as tennis might produce results as varied as tennis-related products, the history of tennis, tennis rankings, tennis clubs, and tennis lessons. To avoid sifting through irrelevant links, use the more specific phrase "tennis lessons."

Boolean Logic

Boolean logic, named after nineteenth-century mathematician George Boole, is a form of algebra in which all values are reduced to TRUE or FALSE. This logic system can be applied to search engine keywords in order to find only the most pertinent results. Boolean operators, or the conventions used in keywords to apply Boolean logic to Internet searches, are as follows:

• To find Web pages with an exact phrase, place the keyword or phrase in quotation marks. Phrases in quotation marks such as "Boston terriers" and "Siamese cats" will only produce Web pages that include that exact phrase.
• You can search for Web pages that include two or more keywords, although the words will not always be near each other on the Web page. To do such a search, use the following Boolean operators: AND, +, & You can also simply include a space between words. The following are examples: cats AND dogs, cats & dogs, cats + dogs, cats dogs. These phrases will only produce Web pages about both cats and dogs.
• To search for Web pages with one or both keywords, use the following Boolean operators: OR, ^. Examples of keywords with these Boolean operators are lizards OR snakes, lizards ^ snakes. These phrases will produce Web pages that refer to lizards, snakes, or both.
• To find results with one but not another keyword, use the following Boolean operators: NOT, -. Examples are cats NOT tigers, cats -tigers. These phrases will produce results about all cats except tigers.
• If you are looking for a combination of specific information, you can use a combination of Boolean operators, such as "pet care" + lizards OR snakes. This phrase will produce Web pages about pet care for lizards or pet care for snakes.

1			For whom was the term Boolean logic named?
2			What is Boolean logic?
3			Which keywords would you use to find Web pages about earthquakes and tornadoes?
4			Which keywords would you use to find Web pages about tennis, excluding tennis lessons?