Remember that internal validity is the extent to which a study allows you to infer causation. Below are four types of study designs. Rand them from lowest (1) to the highest (4) in terms on their...

Remember that internal validity is the extent to which a study allows you to infer causation. Below are four types of study designs. Rand them from lowest (1) to the highest (4) in terms on their internal validity?

experimental, cross-sectional study, case- control study, qualitative intervention