The overalternating bias is that people rate sequences with an excess of alternation as more random than prescribed by information theory. There are two main explanations: the representativeness heuristic (Kahneman & Tversky Cognitive Psychology, 3, 430–454, 1972) and the implicit encoding hypothesis (Falk & Konold Psychological Review, 104, 301–318, 1997). These hypotheses are associated with different reaction times predictions. According to the encoding hypothesis, reaction times should increase as the complexity of the sequence increases, whereas the representativeness heuristic predicts fast reaction times only for more complex sequences that appear more random. We asked participants to guess the generating source of pairs of sequences of dichotomous elements in two different conditions: selecting the string generated by a random source or selecting the string generated by a nonrandom source. Results suggest that both the encoding strategy and the representativeness heuristic have a role in randomness perception and that the two criteria may have a different weight when determining the randomness versus the regularity of a string.

过度交替偏差是人们认为过度交替的序列比信息论规定的更随机。主要有两种解释：代表性启发式 (Kahneman & Tversky Cognitive Psychology, 3, 430–454, 1972) 和内隐编码假设 (Falk & Konold Psychological Review, 104,301-318，1997）。这些假设与不同的反应时间预测相关。根据编码假设，反应时间应该随着序列复杂性的增加而增加，而代表性启发式预测仅对出现更随机的更复杂序列的快速反应时间。我们要求参与者在两种不同的条件下猜测成对的二分元素序列的生成源：选择由随机源生成的字符串或选择由非随机源生成的字符串。结果表明，编码策略和代表性启发式都在随机性感知中起作用，并且在确定字符串的随机性与规则性时，这两个标准可能具有不同的权重。