A researcher is unable to retest some of his participants in a before-after design because they have dropped out of the program. This is an example of a(n) ________threat.

Question

Quizplus · Accepted Answer

Attrition threat refers to the issue of participants dropping out of a study over time, which can affect the validity of the results, especially in before-after design studies.

A Researcher Is Unable to Retest Some of His Participants