Which statistic estimates the average of all the possible split-half correlations but can only be used when each question has only two response alternatives?
A) The Spearman-Brown formula
B) The Kuder-Richardson formula 20
C) Cronbach's alpha
D) Cohen's kappa

Question

Quizplus · Accepted Answer

The Kuder-Richardson formula 20 estimates the average of all possible split-half correlations for a test with dichotomous items (each question has only two response alternatives). Therefore, it is the best choice in this scenario. The Spearman-Brown formula and Cronbach's alpha are used for tests with more than two response alternatives, while Cohen's kappa is a measure of inter-rater reliability.

Which Statistic Estimates the Average of All the Possible Split-Half