Show that the pretest-posttest design is flawed


Students are too easily swayed by pre-post designs. One way to illustrate the general problem with these designs is to give students a list of words to memorize, test them on this list (pretest), introduce an absurd memory treatment ("Touch your finger to your nose"), then test them on a second list of words (posttest).

If you use two identical lists, they should do better on the second list because of practice.

If you use two similar lists, they should perform worse on the second list because of proactive interference.


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