It happens occasionally that a student who is in one of our classes has previously taken the class from another instructor.The repeater students will comment that the class is so much easier with us as instructors.Now, we might want to believe that we are such great instructors that student learning the dependent variable) has drastically improved because of us the independent variable).However, which threat to internal validity better explains the increase in student learning?
A)attrition
B)testing
C)diffusion of treatment
D)instrumentation

Question

Quizplus · Accepted Answer

Testing is the correct answer because it refers to the effect of taking a test on the scores of subsequent tests. In this context, students who have previously taken the class (and presumably its tests and assignments) may perform better the second time around not necessarily because of improved teaching methods, but because they are already familiar with the material and the types of questions they might be asked. This familiarity can lead to an increase in student learning outcomes that is actually due to prior exposure to the test material rather than the instructional quality.

It Happens Occasionally That a Student Who Is in One