A hypothesis-testing procedure that is used to evaluate mean differences between multiple treatments (or populations)
Analysis of variance
variation in observations that are the result of factors related to the experimental differences between groups
systematic variability
the variability that arises from differences between groups, which includes treatment effects and error
between groups variability
a series of t tests performed on each pair of group means with a modified alpha level
Bonferroni test
An analysis of variance that uses multiple grouping variables, instead of just one, to look for group mean differences
factorial ANOVA
the mean of a group of averages
grand mean
used to categorize data into groups
grouping variable
A sample variance that measures the mean of the squared deviations
mean square
thought to change as a function of changes in a predictor (independent) variable
outcome variable
A test that is conducted after an ANOVA with more than two treatment conditions where the null hypothesis was rejected
post hoc test
Any deviations between a person and that person’s group mean caused only by chance
random error
An analysis of variance that measures each study subject three or more times to look for a change
repeated measures ANOVA
A post hoc test for ANOVA that uses an F ratio to evaluate the significance of the difference between any two treatment conditions
Scheffé test
The reasons that scores differ from one another
sources of variability
A popular post hoc analysis for ANOVA that makes adjustments based on the number of comparisons
Tukey’s honestly significant difference
The variability that arises from differences that occur within each group due to individual differences among participants
within-groups variability
