A researcher calculates eta-squared as being 0.45. Which of the following is the best interpretation of this statistic?
A) We have a 45% chance of rejecting the null hypothesis.
B) The group with the lowest mean value is 45% as large as the group with the highest mean value.
C) Means this different between groups will occur by chance alone 45% of the time.
D) Knowing which group a case belongs to helps reduce errors in prediction by 45%.

Question

Quizplus · Accepted Answer

Eta-squared (η²) is a measure of effect size that indicates the proportion of variance in the dependent variable that is attributable to the independent variable. An η² of 0.45 means that 45% of the variance in the dependent variable can be explained by the group membership, thus reducing prediction errors by 45%.

A Researcher Calculates Eta-Squared as Being 0