When random assignment fails to create equivalent groups,the problem of _____ occurs.
A)sampling error
B)self-selection
C)third variables
D)external validity

Question

Quizplus · Accepted Answer

Third variables can affect the outcome of an experiment if they are not controlled or equalized between groups. When random assignment fails to create equivalent groups, it often means that one or more relevant third variables are unevenly distributed across the groups, leading to confounding variables that can affect the internal validity of the study. Sampling error refers to the natural variability or chance fluctuations in the sample that affect the representativeness or accuracy of the results. Self-selection refers to the bias or non-randomness introduced by participants who choose whether or not to participate in a study based on their own characteristics or preferences. External validity refers to the generalizability or applicability of the results to other populations, settings, or conditions. While external validity can be compromised by confounding variables, it is not directly related to the problem of non-equivalent groups.

When Random Assignment Fails to Create Equivalent Groups,the Problem of _____