Validating the intended interpretations for proposed uses of tests scores is paramount for making valid inferences in educational and psychological research. Ascertaining measurement invariance for measurement instruments is an assumption for comparing means. If measurement invariance does not hold for groups of interest, comparison of means will…

Supplemental Instruction (SI) is a programme that is attached to difficult courses with the objective of increasing student performance and retention. However, an SI programme also has the potential to increase overall student performance and retention during the first critical year if applied to introductory courses. In this study the latter…