Researchers are often inclined to test agreement or discrepancy hypotheses using difference scores. This commentary explains 2 mathematical-statistical principles underlying associations with difference scores and 2 conceptual-interpretation problems that make difference scores inappropriate for testing such hypotheses. The commentary provides…

The use of differences scores to assess agreement/disagreement has a long and contentious history. Laird (2020) notes, however, that developmentalists have been particularly resistant to discontinue the use of difference scores. One area of developmental science where difference scores are still in regular use is that of parental differential…

There is substantial variance in the age at which children construct and deploy their first explicit theory of biology. This study tests the hypothesis that this variance is due, at least in part, to individual differences in their executive function (EF) abilities. A group of 79 boys and girls aged 5-7 years (with a mean age of 6½ years) were…

This article sought to examine the differences between transfer and nontransfer students on mental health factors, social involvement, and academic success. It was found that transfer students had significantly higher scores on several mental health factors as compared to nontransfer students. It was also found that transfer students were less…

This report examines the differences in impact estimates and standard errors that arise when these are derived using state achievement tests only (as pre-tests and post-tests), study-administered tests only, or some combination of state- and study-administered tests. State tests may yield different evaluation results relative to a test that is…