中文摘要：

通过两个实验来探讨随机序列中的近因效应 。在实验1中,采用传统实验范式,让被试进行一系列的抛掷硬币结果的猜测并给予反馈,结果发现：（1）在最近连续几次硬币呈现的结果不同时,人们通常把各个结果分别作为独立的单元来看待,大部分情况下做出随机性的预期;（2）在最近连续几次硬币呈现的结果相同时,人们通常把连续几次相同的结果作为一个认知单元来看待,在最近猜测对错两种情况下分别出现了截然相反的两种近因效应。当最近1次猜对时,对下一结果的预期出现正近因效应即热手谬误,但是最近几次连续猜对时谬误减少乃至消失;当最近1次猜错时,对下一结果的预期出现负近因效应即赌徒谬误,并且最近几次连续猜错时负近因效应并未受到太大影响。实验2在实验1范式的基础上,把硬币抛掷的结果人为分组,发现被试对每一组的第一个结果做出预期时,实验1中的各种效应均消失,该现象支持关于随机序列知觉的“格式塔理论”。

英文摘要：

The researchers have studied the recency effect in the random sequences perception. It was thought people had two kinds of opposing expectations： the positive recency （the hot hand fallacy ） and the negative recency （the gambler＇s fallacy）. The existing studies focused on when the two effects would appear and how they would exchange with each other. Kahneman＇s ＂local representativeness heuristic＂ （1971） was the first cognitive explanation of the recency effect. They identified the ＂law of small numbers＂, which is the erroneous belief that properties of large samples also apply to very small samples, and the ＂law of small numbers＂ was the strategy in the predicting process. Moldoveanu and Leager （2002） tried to explain the effect with the casual model. Roney and Trick （2003） gave the Gestalt explanation. They thought that the random sequence recency involved two stages. The first one was about whether to consider the present and former outcomes as a group; when the outcomes were considered as a Gestalt, the perception entered the second stage, in which the subjects would decide the possible relationship between the present and former outcomes. However, Trick didn＇t explain the dividing strategy of the random sequences. Our study aims to examine the Gestalt theory and the hypothesis that the dividing is based on the continuation of the same outcomes in the random sequences. That is, in the coin sequences, when the last outcomes are the same （all heads or all tails）, the subjects would incline to consider these outcomes as a cognitive group or unit; while the last outcomes are different, they would be divided into different cognitive units. Moreover, the right/wrong sequences of the expectation make up another random binary series. The dividing of the right/wrong sequences is also based on the continuation. The outcomes of the coin and the right/wrong results are divided with the continuation strategy, and then form the different cognitive units depending on three factors-