If an evaluator judges the rate of success of a program on the basis of those who complete the program, she is likely to be failing to deal with the threat to internal validity called
A) attrition.
B) regression to the mean.
C) testing.
D) history.

Question

Quizplus · Accepted Answer

Judging the success of a program based only on those who complete it ignores the issue of attrition, which can significantly affect the internal validity of the evaluation. Attrition refers to the loss of participants from a study, which can introduce bias if those who drop out are systematically different from those who continue. Therefore, it is important to account for attrition when evaluating the success of a program.

If an Evaluator Judges the Rate of Success of a Program