People tend to think that streaks in random sequential events are rare and remarkable. When they actually encounter streaks, they tend to consider the underlying process as non-random. The present paper examines the time of pattern occurrences in sequences of Bernoulli trials, and shows that among all patterns of the same length, a streak is the…

Gain analysis is applied to the invention of the sewing needle as well as different sewing implements and modes of sewing. The analysis includes a two-subject experiment. To validate the generality of gain heuristics and underlying switching processes, the invention of the assembly line is also analyzed. (TJH)

Examines tasks from the heuristics and biases literature in light of the understanding/acceptance principle of P. Slovic and A. Tversky (1974). Shows how the variation and instability of responses can be analyzed to yield inferences about why descriptive and normative models of human reasoning and decision making sometimes do not coincide.…

Proposes a probability heuristic model for syllogistic reasoning and confirms the rationality of this heuristic by an analysis of the probabilistic validity of syllogistic reasoning that treats logical inference as a limiting case of probabilistic inference. Meta-analysis and two experiments involving 40 adult participants and using generalized…

Research on language comprehension has focused on the resolution of syntactic ambiguities, and most studies have employed garden-path sentences to determine the system's preferences and to assess its use of nonsyntactic sources information. A topic that has been neglected is how syntactically challenging but essentially unambiguous sentences are…

Philosophers of biology have long argued that Darwin's theory of evolution was qualitatively different from all earlier theories of evolution. Whereas Darwin's predecessors and contemporaries explained adaptation as the transformation of a species' ''essence,'' Darwin explained adaptation as the selective propagation of randomly occurring…

A framework is presented for characterizing competence for cognitive tasks, with a detailed hypothesis about competence for counting by typical 5-year-old children. It is proposed that competence has three main components that are called conceptual, procedural, and utilizational competence. Conceptual competence, which is discussed in greatest…

Five experiments involving a total of 268 college students indicate that people are especially likely to overinfer quantity or probability from numerosity when they are asked to make inherently difficult judgments, when they are asked to render judgments while performing a concurrent task, and when they are forced to make rapid judgments. (SLD)

Gigerenzer (2000) and Anderson (1990) analyzed reasoning by asking: what are the reasoner's goals? This emphasizes the adaptiveness of behavior rather than whether a belief is normative. Belief in the ''hot hand'' in basketball suggests that players experiencing streaks should be given more shots, but this has been seen as a fallacy due to…

Two experiments, with 300 adult women as subjects, studied the effects of laboratory training on the use of the Conjunction Rule, a principle of probability that is often violated. Learning alternative strategies enabled trained subjects to use extensional reasoning rather than intensional heuristics. (SLD)

Attaining the insight needed to solve the Mutilated Checkerboard problem, which requires discovery of an effective problem representation (EPR), is described. Performance on insight problems can be predicted from the availability of generators and constraints in the search for an EPR. Data for 23 undergraduates were analyzed. (TJH)

Studied developmental differences in the search constraint heuristics used in scientific reasoning using 12 undergraduates, 20 community college students, 17 fifth to seventh graders (grade 6), and 15 third graders taught to use a programmable robot. Adults use domain-general skills that go beyond the logic of confirmation and disconfirmation.…