List I | List II | ||
A. | Placebo effect | I. | We can draw clear causal conclusion from an experiment |
B. | High external validity | II. | The results of a study generalize to other settings and populations |
C. | Double-blind procedure | III. | Participant improves because of the expectation of receiving a treatment, not because of the treatment itself |
D. | High internal validity | IV. | Neither researchers nor participants IV. know the condition to which each participant is assigned |