Activity #5

Sharon Hutchins performs several demonstrations and activities that help students to understand the fallibility of inferential processes and memory. In doing this, she makes use of perceptual illusions, cognitive illusions (see M. Piattelli-Palmarini, 1994, "Inevitable Illusions: How Mistakes of Reason Rule Our Minds." Wiley), and activities that show influences on the formation of false memories (such as the Deese-Roediger-McDermott lists mentioned by Michale Kane above).

Wed, 17 May 2000
Sharon Hutchins
Denison University
hutchins@cc.denison.edu

I'd like to "plug" the effectiveness of some simple demonstrations. I use the following three in both Intro Psych and Research Methods classes to illustrate WHY the scientific method is important. The first, very commonly done among psychologists, is to have the students judge line length, object size, make color judgments, etc., and include in the stimuli visual illusions of various types (Ponzo, Ames room, etc.). I also include some figures illustrating Gestalt principles of organization and context effects, including ambiguous figures. For many items I give different stimuli or instructions to different students, then at the end have the students report what they've seen, and they are amazed that others come up with different answers or that most students are wrong (on the illusions). They do seem to appreciate that their perceptions are not always accurate.

The second demo/lab I do is on logical thinking. I include items that illustrate well-known problem-solving and decision-making errors, like the framing effect, the Weson card demo (with the beer/age counter-example), problems with conditional probabilities, the availability and representativeness heuristics, and so on. I collect the answers, and the distribute the number of correct answers across the class for each problem (which are invariably quite low). This also seems quite effective in illustrating to the students that even they (smart college students) have certain biases and errors in thinking. The important thing, I've found, is to tie this back in with the scientific method. I like to use an analogy that the scientific method is designed to correct limitations in human thinking like a microscope and telescope are designed to correct limitations of human vision. This seems to make sense to the students and gives them a reason why they ought to learn the "boring" methodology information. In turn, this seems to make them better at critically evaluating their intuitions and assumptions.

A third effective demo is on problems with memory. I've found combining a replication of false memory with word lists from Roediger & McDermott (1995), with an eyewitness memory demonstration from Gee & Dyck (1988) (Using a videotape clip to demonstrate the fallibility of eyewitness testimony. Teaching of Psychology, 25(2), 138-140), which I've amplified to include a section where the students describe the perpetrator and his actions (including some leading questions), is quite effective in getting students to realize their observations and memories are faulty.