Intuitive t tests: Lay use of statistical information Authors
Received: 18 August 2006 Accepted: 26 February 2007 DOI:
10.3758/BF03193104 Cite this article as: Obrecht, N.A., Chapman, G.B. & Gelman, R. Psychonomic Bulletin & Review (2007) 14: 1147. doi:10.3758/BF03193104 Abstract
Normatively, a statistical pairwise comparison is a function of the mean, standard deviation (
SD), and sample size of the data. In our experiment, 203 undergraduates compared product pairs and judged their confidence that one product was better than the other. We experimentally manipulated (within subjects) the average product ratings, the number of raters (sample size), and the SD of the ratings. Each factor had two levels selected, so that the same change in statistical power resulted from moving from the low to the high level. We also manipulated (between subjects) whether subjects were given only the product rating data as summarized in a statistical format or the summaries plus the raw ratings. Subjects gave the most weight to mean product ratings, less weight to sample size, and very little weight to SD. Providing subjects with raw data did not increase their use of sample size and SD, as predicted.
This project was supported by NSF Grant SES-03-25080 to the second author, NSF Grant REC-9720410 to the third author, and a Rutgers University excellence fellowship awarded to the first author
Download to read the full article text References Frederick, S.
(2005). Cognitive reflection and decision making.
Journal of Economic Perspectives
CrossRef Gallistel, C. R., & Gelman, R. (2005). Mathematical cognition. In K. Holyoak & R. Morrison (Eds.), The Cambridge handbook of thinking and reasoning (pp. 559–588). Cambridge: Cambridge University Press. Gigerenzer, G. (2000). Adaptive thinking: Rationality in the real world. New York: Oxford University Press. Gigerenzer, G.
(2003). Simple tools for understanding risks: From innumeracy to insight.
British Medical Journal
CrossRef PubMed Gigerenzer, G.
(1995). How to improve Bayesian reasoning without instruction: Frequency formats.
CrossRef Glover, S.
(2004). Likelihood ratios: A simple and flexible statistic for empirical psychologists.
Psychonomic Bulletin & Review
CrossRef Gottlieb, D., Weiss, T.
Chapman, G. B.
(2007). The format in which uncertainty information is presented affects decision biases.
CrossRef PubMed Hartnett, P. M.
(1998). Early understandings of numbers: Paths or barriers to the construction of new understandings?
Learning & Instruction
CrossRef Hertwig, R., Barron, G., Weber, E.
(2004). Decisions from experience and the effect of rare events in risky choice.
CrossRef PubMed Hertwig, R.
(1999). The “conjunction fallacy” revisited: How intelligent inferences look like reasoning errors.
Journal of Behavioral Decision Making
CrossRef Hoffrage, U.
(1998). Using natural frequencies to improve diagnostic inferences.
CrossRef PubMed Hoffrage, U., Lindsey, S., Hertwig, R.
(2000). Communicating statistical information.
CrossRef PubMed Kahneman, D.
(1972). Subjective probability: A judgment of representativeness.
CrossRef Lenth, R. V. (2006). Java applets for power and sample size [Computer software]. Retrieved January 2006 from www.stat.uiowa. edu/≈rlenth/Power. Nisbett, R. E., Krantz, D. H., Jepson, C.
(1983). The use of statistical heuristics in everyday inductive reasoning.
CrossRef Obrecht, N. A., & Chapman, G. B. (2006, November). Intuitive t tests: Lay use of statistical information. Poster session presented at the Psychonomic Society Annual Meeting, Houston, TX. Obrecht, N. A., Chapman, G. B., & Gelman, R. (2006, November). Statistical reasoning is influenced by serial presentation of information. Paper presented at the annual meeting of the Society for Judgment and Decision Making, Houston. Sedlmeier, P.
(1997). Intuitions about sample size: The empirical law of large numbers.
Journal of Behavioral Decision Making
CrossRef Sedlmeier, P.
(2001). Teaching Bayesian reasoning in less than two hours.
Journal of Experimental Psychology
PubMed Tversky, A.
(1974). Judgment under uncertainty: Heuristics and biases.
CrossRef PubMed Copyright information
© Psychonomic Society, Inc. 2007