What is the major problem associated with self-selection as a way to assign participants to the experimental and control groups?
A)The treatment necessarily will work in the experimental group because those participants are especially motivated.
B)The two groups probably will differ on many variables besides whether or not they received the treatment.
C)Self-selection violates the requirement for informed consent.
D)Self-selection prevents the manipulation of the independent variable and measurement of the dependent variable.

Question

Quizplus · Accepted Answer

Self-selection can result in systematic differences between the experimental and control groups, making it difficult to determine if the treatment caused any observed differences. The groups may differ in important ways (e.g. age, gender, socioeconomic status, motivation) that are unrelated to the treatment being tested. This confounding of variables can make it difficult to isolate the effect of the treatment itself.

What Is the Major Problem Associated with Self-Selection as a Way