Exhibit 11-4.Identify the major threat to internal validity in the following research studies.
-Refer to Exhibit 11-4.A researcher conducted a semester-long experiment comparing two instructional programs in math.During the administration of tests during the semester, the researcher found that about ten percent of the experimental group and about five percent of the control group were absent for each administration.
A) Regression
B) Diffusion
C) Mortality
D) Selection
E) History

Question

Quizplus · Accepted Answer

The major threat to internal validity in this study is mortality, as there was differential attrition (absenteeism) in the experimental and control groups. This could potentially affect the results by introducing a bias towards the group with more participants remaining in the study, and therefore invalidate the conclusions drawn from the study.