Attrition is a problem for longitudinal studies because
A) all participants are not at equal risk of being lost from the study over time.
B) you cannot add new measures to the study as it goes on.
C) all groups in the study must be as much the same as you can possibly make them.
D) it creates a cohort effect among the participants.

Question

Quizplus · Accepted Answer

Attrition (the loss of participants over time) can create bias in the sample because individuals who drop out of the study may be systematically different from those who remain in the study. Participants at higher risk of dropping out may have different characteristics or experiences that could impact the study results. Therefore, attrition is a problem for longitudinal studies because it can affect the validity and generalizability of the findings. Choices B, C, and D are not directly related to the issue of attrition in longitudinal studies.

Attrition Is a Problem for Longitudinal Studies Because