Which of the following is a threat to internal validity?
A) Differential selection of participants
B) Selection-treatment interaction
C) Posttest sensitization
D) Multiple-treatment interference

Question

Quizplus · Accepted Answer

Differential selection of participants is a threat to internal validity because it can lead to differences between the treatment and control groups that are not due to the treatment itself. For example, if the treatment group is more likely to be composed of people who are motivated to change, then the treatment may appear to be more effective than it actually is.

Which of the Following Is a Threat to Internal Validity