Which of the following research methods is MOST susceptible to threats to internal validity?

Question

Quizplus · Accepted Answer

Experiments are the most susceptible to threats to internal validity because they involve manipulating an independent variable to see its effect on a dependent variable. However, extraneous variables or confounding variables can potentially affect the dependent variable, leading to inaccurate conclusions. Various methods such as random assignment and control groups are employed to minimize the effect of these potential confounds.

Which of the Following Research Methods Is MOST Susceptible to Threats