Assessment, Statistics, and Research

  A post hoc test is a statistical test used to determine if a pair of values are significantly different from each other after the primary analysis has been completed. Post Hoc Tests / Suttong.com AI Infographic The term post hoc is a Latin phrase meaning "after the event." A common use of post hoc tests is the comparison of group means following an F -test in an ANOVA has revealed significant differences among the groups. The reason to test for differences after an overall test like ANOVA is to reduce the risk of finding a significant difference by chance. That is, if researchers perform a large number of tests on a sample, they may find one or more tests yield significant results by chance. There are many post hoc tests. Following are some examples of tests that compare the means of two groups. Bonferroni Test This is a popular test. By dividing the significance level by the number of comparisons, the risk of finding a significant difference by chance is reduced. This proc...

ANOVA stands for Analysis of Variance. Although the term “variance” will be explained later, for now you can think of it simply as differences. ANOVA procedures examine differences in scores among groups of people who complete a test, survey, or any measurable task (Sutton, 2021, January 5). Cite this Post Sutton, G. W. (2021, January 5). ANOVA in counseling & psychology research. Assessment, Statistics, and Research .  https://statistics.suttong.com/2021/01/anova-in-counseling-psychology-research.html What's in this post? ANOVA defined What ANOVA does Types of ANOVA Understanding the F value When to use ANOVA A conceptual example A worked example A sample write-up A One-Way ANOVA Calculator ********** What ANOVA Does ANOVA evaluates whether group means differ more than we would expect by chance. For example, imagine a study examining the effects of three room temperatures on math performance: • Independent Variable (IV): Temperature ◦ Levels: 75°, 85°, 95° Fahrenheit •...