A study is internally valid to the extent that which of the following has taken place?

Question

A) All alternative explanations to the independent variable as the cause of outcomes can be ruled out
B) A true experimental design was used
C) Intervention fidelity was maintained
D) A strong counterfactual was established

Answer 1

A
Feedback:
Internal validity is the extent to which it can be inferred that the independent variable is truly causing the outcome. Experiments (or randomized controlled trials, RCTs) involve an intervention (the researcher manipulates the independent variable by introducing an intervention; control (including the use of a control group that is not given the intervention and represents the comparative counterfactual); and randomization or random assignment (with participants allocated to experimental and control groups at random to make the groups comparable at the outset). Intervention fidelity helps to avert biases and gives potential benefits a full opportunity to be realized. A counterfactual is what would have happened to the same people simultaneously exposed and not exposed to a causal factor. The effect is the difference between the two. A good research design for cause-probing questions entails finding a good approximation to the idealized counterfactual.