Gain Scores, Analysis of

Gain (i.e., change, difference) is defined here as the difference between test scores obtained for an individual or group of individuals from a measurement instrument, intended to measure the same attribute, trait, concept, construct, or skill, between two or more testing occasions. This difference does not necessarily mean that there is an increase in the test score(s). Thus, a negative difference is also described as a “gain score.” There are a multitude of reasons for measuring gain: (a) to evaluate the effects of instruction or other treatments over time, (b) to find variables that correlate with change for developing a criterion variable in an attempt to answer questions such as “What kinds of students grow fastest on the trait of interest?,” and (c) to compare ...