During the course of her experiment, Yolanda learned that seven of the 12 clients in her new four-hour session had quit and walked out of the session before it was completed. What threat to internal validity does her experiment have?

Question

Quizplus · Accepted Answer

Experimental mortality refers to the loss of participants during the course of an experiment, which can threaten the internal validity by making it unclear whether the outcomes were due to the experimental intervention or the loss of participants. In Yolanda's case, the fact that seven out of 12 clients quit before completing the session is a classic example of experimental mortality.

During the Course of Her Experiment, Yolanda Learned That Seven