Price Paul C, Kimura Nicole M, Smith Andrew R, Marshall Lindsay D
Department of Psychology, California State University, Fresno.
Department of Psychology, Appalachian State University.
J Exp Psychol Learn Mem Cogn. 2014 Sep;40(5):1321-31. doi: 10.1037/a0036576. Epub 2014 Apr 21.
Previous research has shown that people exhibit a sample size bias when judging the average of a set of stimuli on a single dimension. The more stimuli there are in the set, the greater people judge the average to be. This effect has been demonstrated reliably for judgments of the average likelihood that groups of people will experience negative, positive, and neutral events (Price, 2001; Price, Smith, & Lench, 2006) and also for estimates of the mean of sets of numbers (Smith & Price, 2010). The present research focuses on whether this effect is observed for judgments of average on a perceptual dimension. In 5 experiments we show that people's judgments of the average size of the squares in a set increase as the number of squares in the set increases. This effect occurs regardless of whether the squares in each set are presented simultaneously or sequentially; whether the squares in each set are different sizes or all the same size; and whether the response is a rating of size, an estimate of area, or a comparative judgment. These results are consistent with a priming account of the sample size bias, in which the sample size activates a representation of magnitude that directly biases the judgment of average.
先前的研究表明，人们在判断一组单一维度刺激的平均值时会表现出样本量偏差。集合中的刺激越多，人们判断的平均值就越大。这种效应在对人群经历负面、正面和中性事件的平均可能性的判断中得到了可靠的证明（普赖斯，2001年；普赖斯、史密斯和伦奇，2006年），在对数字集合平均值的估计中也得到了证明（史密斯和普赖斯，2010年）。本研究关注的是在感知维度上对平均值的判断是否会观察到这种效应。在5个实验中，我们表明，随着集合中方块数量的增加，人们对集合中方块平均大小的判断也会增加。无论每个集合中的方块是同时呈现还是依次呈现；无论每个集合中的方块大小不同还是全部相同；以及无论反应是大小评级、面积估计还是比较判断，这种效应都会出现。这些结果与样本量偏差的启动解释一致，在这种解释中，样本量激活了一个大小表征，该表征直接使平均值的判断产生偏差。
