A researcher reports an F-ratio with df= 2, 12 for a repeated measures of ANOVA.


a. How many treatment conditions were compared in the study?

b. How many individuals participated in the study?

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To determine the answers to these questions, we need to understand how the degrees of freedom (df) in an F-ratio are calculated for a repeated measures ANOVA.

In a repeated measures ANOVA, the F-ratio is calculated by comparing the variance between treatment conditions to the variance within treatment conditions.

a. To determine the number of treatment conditions compared in the study, we need to look at the df numerator of the F-ratio. Here, df = 2. The numerator df represents the degrees of freedom associated with the between-group variance. In a repeated measures ANOVA, the numerator df is equal to the number of treatment conditions minus 1. Therefore, the number of treatment conditions compared in the study is 2 + 1 = 3.

b. To determine the number of individuals who participated in the study, we need to look at the df denominator of the F-ratio. Here, df = 12. The denominator df represents the degrees of freedom associated with the within-group variance. In a repeated measures ANOVA, the denominator df is equal to the total number of individuals minus the number of treatment conditions. Therefore, the total number of individuals who participated in the study is 12 + 3 = 15.