When different interviewers are used in a pretest from those used in the posttest and this produces different results in the study,this is an example of a(n):
A)history effect
B)mortality effect
C)instrumentation effect
D)cohort effect

Question

Quizplus · Accepted Answer

This is an example of an instrumentation effect, where the change in results is due to a change in the measurement tool, in this case the different interviewers used in the pretest and posttest. A history effect refers to external events that may influence the results, a mortality effect refers to loss of participants during the study, and a cohort effect refers to differences in groups based on the time period they were born or grew up in.

When Different Interviewers Are Used in a Pretest from Those