ANOVA | ANalysis Of VAriance-widely used test to compare two or more groups
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one-way ANOVA | analysis of variance involving only one independent variable
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additivity | the property of variance that, for individual samples, the variance of a sum of parts is equal to the sum of the variances of the parts
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key deviations | for the one-way ANOVA, the key deviations are between each score in a group and the group's mean and between each group mean and the total mean
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total variability | variability in data based on the deviation between each score and the total mean
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within-groups variability | part of the ANOVA test based on the deviation between each score in a group and the group mean; variability within a group
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individual differences | differences between experimental participants because of different participant backgrounds, experiences, abilities, motives, etc.
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experimental error | source of variability in data caused by such things as imprecise measuring equipment, momentary changes in experimenter and subject attention, and slight changes in background conditions during data collection
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between-groups variability | part of the ANOVA test based on the deviation between each group mean and the total mean; variability between the groups
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treatment effect | variability in data caused by administration of the independent variable
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total sum of squares | sum of the squared deviation of each score from the total mean in the analysis of variance
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within-groups sum of squares | the sum of the squared deviations of each score in a group from its group mean, with the squared deviations summed across groups
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between-groups sum of squares | the square of the deviation between each group mean and the total mean multiplied by the number of subjects in a particular group and summed over groups
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ANOVA summary table | table used to summarize the results of the analysis of variance
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mean square | the analyzed variance in the ANOVA test, found by dividing each sum of squares by the appropriate df
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F ratio | ratio of the variability between groups to the variability within groups; test statistic for the ANOVA test
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post-ANOVA tests | unplanned group comparisons following a significant F ratio
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a posteriori test | same as post-ANOVA test
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post hoc test | same as post-ANOVA test
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a priori test | test designed to look at specific hypotheses before the experiment is done
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Fisher LSD test | least significant difference test; powerful post-ANOVA test that compares pairwise differences in means with a computed least significant difference
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protected t test | another name for the Fisher LSD test
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pairwise comparisons | comparing several groups one pair at a time
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Tukey HSD test | post-ANOVA test that compares each mean difference with a computed HSD, or honestly significant difference
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studentized range statistic | statistic sometimes used instead of the F statistic for making group comparisons
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repeated measures ANOVA | form of the ANOVA test used in situations in which the same (or matched) participants are tested on more than two occasions
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