The major threat to internal validity in a causal-comparative study is:
A) location
B) subject characteristics
C) data collector bias
D) instrument decay

Question

Quizplus · Accepted Answer

Subject characteristics are a major threat to internal validity in causal-comparative studies because differences between groups other than the independent variable can affect the outcome, making it difficult to attribute differences in the dependent variable directly to the independent variable.

The Major Threat to Internal Validity in a Causal-Comparative Study