login

Intuitivet tests: Lay use of statistical information

Psychonomic Bulletin & ReviewPublished 1 December 2007Open access
Natalie A. Obrecht, Gretchen B. Chapman, Rochel Gelman
Citations73
SJR quartileQ1
SJR score1.97
SNIP2.21
View PDF

TL;DR

In this experiment, 203 undergraduates compared product pairs and judged their confidence that one product was better than the other, and experimentally manipulated the average product ratings, the number of raters, and theSD of the ratings.

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 thatone product was better than the other. We experimentally manipulated (within subjects) theaverage productratings, 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 orthe summariesplus 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.

Keywords

Computer ScienceDecision Sciences