Final answer:
When two groups differ on a factor unrelated to the test, such as gender, it is important to consider this factor as a potential lurking variable that may influence the observed differences in test scores.
Step-by-step explanation:
When two groups differ on a factor unrelated to the test, like gender, it is important to consider this factor as a potential lurking variable. Lurking variables are variables that may affect the outcome of a study but are not directly measured or controlled. In this case, gender could be a lurking variable that influences the test scores of the two groups.
For example, if one group is predominantly male and the other group is predominantly female, the differences in test scores may not be solely attributed to the test itself. The gender differences, such as societal expectations or educational opportunities, could contribute to the variations in performance.
Therefore, the assumption that can be made is that the observed differences in test scores between the two groups may be influenced by factors unrelated to the test, such as gender.