When the comparison group is in some way affected by, or affects, the treatment group, this has occurred ______.

Question

Quizplus · Accepted Answer

Contamination occurs when the comparison group is affected by or affects the treatment group, causing the results of the study to be skewed. This can often happen in studies where participants are not randomly assigned to groups, or when the treatment group and comparison group are located in close proximity to one another.

When the Comparison Group Is in Some Way Affected By