When the data form a 2×2 matrix,the phi-coefficient is used to measure effect size for the chi-square test for independence.If other factors are held constant,how does sample size influence the values for phi and chi-square?
A)A larger sample increases both phi and chi-square.
B)A larger sample increases phi but has no effect on chi-square.
C)A larger sample increases chi-square but has no effect on phi.
D)Sample size does not influence either phi or chi-square.

Question

Quizplus · Accepted Answer

A larger sample size increases the chi-square value because chi-square is influenced by the frequencies observed in the cells, which increase with sample size. However, the phi coefficient, which is a measure of effect size, is designed to be independent of sample size, thus it is not affected by changes in sample size.

When the Data Form a 2×2 Matrix,the Phi-Coefficient Is Used