Voracek Martin, Tran Ulrich S, Formann Anton K
School of Psychology, University of Vienna, Austria.
Percept Mot Skills. 2008 Feb;106(1):91-103. doi: 10.2466/pms.106.1.91-103.
Subjective estimates and associated confidence ratings for the solutions of some classic occupancy problems were studied in samples of 721 psychology undergraduates, 39 casino visitors, and 34 casino employees. On tasks varying the classic birthday problem, i.e., the probability P for any coincidence among N individuals sharing the same birthday, clear majorities of respondents markedly overestimated N, given P, and markedly underestimated P, given N. Respondents did notedly better on tasks varying the birthmate problem, i.e., P for the specific coincidence among N individuals of having a birthday today. Psychology students and women did better on both task types, but were less confident about their estimates than casino visitors or per sonnel and men. Several further person variables, such as indicators of topical knowledge and familiarity, were associated with better and more confident performance on birthday problems, but not on birthmate problems. Likewise, higher confidence ratings were related to subjective estimates that were closer to the solutions of birthday problems, but not of birthmate problems. Implications of and possible explanations for these findings, study limitations, directions for further inquiry, and the real-world relevance of ameliorating misconceptions of probability are discussed.
在由721名心理学本科生、39名赌场访客和34名赌场员工组成的样本中，研究了对一些经典占位问题解决方案的主观估计及相关的置信度评级。在改变经典生日问题（即N个人拥有相同生日的任何巧合概率P）的任务中，在给定P的情况下，明显多数的受访者显著高估了N；在给定N的情况下，又显著低估了P。在改变出生同伴问题（即N个人今天过生日的特定巧合概率P）的任务中，受访者的表现明显更好。心理学专业学生和女性在这两种任务类型上表现更好，但比起赌场访客、员工以及男性，他们对自己的估计缺乏信心。几个其他的个体变量，比如主题知识和熟悉程度的指标，与在生日问题上表现更好且更有信心相关，但与出生同伴问题无关。同样，更高的置信度评级与更接近生日问题解决方案的主观估计相关，但与出生同伴问题无关。本文讨论了这些发现的意义及可能的解释、研究局限性、进一步探究的方向，以及纠正概率误解在现实世界中的相关性。
