Gain Scores, Analysis of

The analysis of gain scores is the evaluation of the difference between pretest and posttest scores in terms of treatment versus control design. In other [Page 716]words, this technique is used to determine the effect of a treatment on the difference between pre- and posttest scores compared to a control group. This process involves using analysis of variance (ANOVA) to determine whether the difference between pretest and posttest scores can be predicted by group membership (treatment vs. group). This design is important because it gives the researcher the ability to assess whether a protocol or method improves performance compared to the status quo. This entry discusses the history of analysis of gain scores, when and how gain scores are analyzed, and the limitations of this ...