A Threat to Internal Validity of a Study Using a Two-Group

question 3

Multiple Choice

A threat to internal validity of a study using a two-group pretest-posttest design is that:

• A) external events are extremely likely to affect the outcome of these studies.
• B) people are more likely to drop out of this type of study.
• C) the pretest may sensitize subjects so they change their behavior or responses on the posttest.
• D) there is no way to determine if the groups are alike before starting the study.