Eta squared is a measure of:

Eta squared is a measure of:

• A. Effect size
• B. Statistical power
• C. Test reliability
• D. Degrees of freedom

Answer: (A)

Eta squared is a measure of effect size. In ANOVA, it tells you what proportion of the total variance in the dependent variable is explained by the independent variable. Practically, it shows how big the observed effect is in terms of variability across all observations. It’s calculated as the sum of squares for the effect divided by the total sum of squares, so it falls between 0 and 1, with higher values indicating a larger, more meaningful effect. This is different from statistical power, which is about the probability of detecting an effect if one exists and depends on sample size and alpha. It’s also not about reliability, which concerns measurement consistency, nor about degrees of freedom, which relate to the structure of the test itself. A related measure, partial eta squared, estimates the effect size of a factor after accounting for other factors in the model.

Eta squared is a measure of effect size. In ANOVA, it tells you what proportion of the total variance in the dependent variable is explained by the independent variable. Practically, it shows how big the observed effect is in terms of variability across all observations. It’s calculated as the sum of squares for the effect divided by the total sum of squares, so it falls between 0 and 1, with higher values indicating a larger, more meaningful effect. This is different from statistical power, which is about the probability of detecting an effect if one exists and depends on sample size and alpha. It’s also not about reliability, which concerns measurement consistency, nor about degrees of freedom, which relate to the structure of the test itself. A related measure, partial eta squared, estimates the effect size of a factor after accounting for other factors in the model.