A researcher notices that the participants assigned to the experimental group were less likely to attend the second session in his experiment than those in the control group. The researcher is concerned that __________ might represent a potential threat to the internal validity of her study.
A) history
B) attrition
C) instrumentation
D) maturation

Question

Quizplus · Accepted Answer

Attrition refers to the loss of participants during a study, which can cause bias and threaten the internal validity of the study. In this case, the experimental group had a higher rate of attrition than the control group, which could affect the results of the study. A, C, and D are not relevant to the issue of differential attrition between the groups.

A Researcher Notices That the Participants Assigned to the Experimental