Assessment, Statistics, and Research

In statistics, an effect size ( ES ) indicates the strength of the relationship between two variables. In psychological experiments, researchers are interested in the strength of the effect of the Independent Variable on the Dependent Variable. In psychotherapy studies, researchers may be interested in the effects of treatment on a measure of the dependent variable. A research questions may be framed: How effective is a set of 6 CBT sessions on the reduction of depression? Psychologists have often described effect sizes as small, medium, or large. Cohen's d Cohen's d is a measure of effect size between two groups. The mean of one group is subtracted from a second group and divided by the pooled standard deviation of the two groups. ES = (M1 - M2) / SD Effect Size  Label 0.2     Small 0.5     Medium 0.8     Large Pearson Correlation Coefficient ( r ) 0.1 to 0.3  Small 0.3 to 0.5  Medium 0.5 to 1.0   Large Converting Co...

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 •...