posted by Joyce on .
According to classical test theory, if the observed variance of a test is 50 and the true variance is 40, what is the estimated reliability of the test?
The ratio of true score variance to the observed score variance: 40/50 = 0.80
The ABC Self-Concept Inventory has a split-half reliability coefficient of 0.90, and the XYZ Self-Concept Inventory has a Spearman-Brown reliability coefficient of 0.90. If all other factors are equal, which instrument would you choose to use?