Question

Which of the following is consistent with what r2 represents as a measure of effect size?

the portion of variability in a sample attributable to a treatment effect relative to the total variability in the sample
the portion of variability in a sample attributable to a treatment effect after correcting for sample size
the statistical significance of a treatment effect
the statistical significance of a treatment effect correcting for the alpha level

Answer 1

Answer:

The correct option is: the portion of variability in a sample attributable to a treatment effect relative to the total variability in the sample.

r2 represents the proportion of variance in the dependent variable that can be explained by the independent variable(s). It is a measure of effect size that ranges from 0 to 1, with higher values indicating a stronger relationship between the variables.

Option a is consistent with this definition, as it describes how much of the variability in the sample can be attributed to the treatment effect. Option b is incorrect because r2 does not correct for sample size. Option c and d are also incorrect because they refer to statistical significance, which is different from effect size.