The functional equivalence of problem solving skills

The tower of Hanoi problem is used to show that, even in simple problem environments, numerous distinct solution strategies are available, and different subjects may learn different strategies. Four major classes of solution strategies are described for the problem. Different strategies have different degrees of transferability, place different burdens on short-term memory and on perception, and require different learning processes for their acquisition. The analysis underscores the importance of subject-by-subject analysis of “what is learned” in understanding human behavior in problem-solving situations, and provides a technique for describing subjects' task performance programs in detail.     

Comprehending quantified sentences: The relation between sentence-picture and semantic memory verification

People were timed as they decided whether quantified sentences like All (some) of the round figures are red were true or false of an accompanying picture. The response latency was a function of the quantifier and the relation between the sets mentioned in the subject and predicate of the sentence. The pattern of latencies was similar to the pattern found for sentences that refer to concepts in semantic memory, e.g., All (some) dogs are animals (Meyer, 1970). This result suggests that the same process may be operating in both domains. Two alternative models of the process are considered. One model assumes that the common process consists of computing the relation between the two sets mentioned in the sentence. The other model assumes that the common process consists of comparing the representation of the sentence to the representation of information computed from the second source. Both models are integrated with broader theories of performance in various comprehension tasks.     

Subtraction and the solution of open sentence problems

This paper is concerned with the processes used by children in solving open sentence problems of the form x + u = y (Type 1) and u + x = y (Type 2). Three models for reaction times to these problems are proposed. The first assumes they are solved by an incrementing process, the second assumes a decrementing process, while the third assumes that the subject increments or decrements, depending on which is quickest. Two experiments designed to evaluate these models are reported. It is shown, by means of a series of regression analyses that the third model gives the best account of the success latencies to Type 1 problems. This model predicts that times will be a linear function of the minimum of x and y ? x. It is also shown that none of the models give an adequate account of the latency data for Type 2 problems. Some possible reasons for this difference are discussed, together with some evidence that indicates that Type 1 problems and ordinary subtraction problems are solved by the same process.     

Modeling strategy shifts in a problem-solving task

A computer simulation model was fitted to human laboratory data for the Missionaries and Cannibals task to explain (1) the effects upon problem performance of giving a hint, and (2) the effects of solving the problem a second time after one successful solution had been achieved. Most of the variance in the relative frequencies of different moves can be explained by positing that the effect of the hint, or of previous experience in solving the problem, is to cause subjects to switch more promptly from a strategy of balancing the numbers of missionaries and cannibals on both sides of the river, to a means-ends strategy.     

Self-consciousness, outcome expectancy, and persistence

A study investigated persistence as a function of two variables: the disposition to be self-attentive (called private self-consciousness) and outcome feedback on a prior task that was described as closely related to the target task. More specifically, subjects first completed a concealed-figures test and were told that their performances were either very good or very poor. The second test, which ostensibly measured the same abilities, was an insolvable design problem that is commonly used to measure persistence. Feedback concerning prior outcomes had a direct influence on expectancies for the second task, but persistence on that task was a joint function of feedback and self-consciousness. That is, favorable feedback led to greater persistence than did unfavorable feedback, but only among subjects high in self-consciousness. This finding replicates and extends the results of several previous studies. Discussion centers on the relationship between the present research and an earlier experiment which yielded apparently different results.     

Monaural recall and the right-ear advantage

Lists of eight nonsense syllables were monaurally presented to right-handed men and women for free recall, half to each ear on each trial. Results showed a right-ear advantage (REA) in the recall of recency items, but not primacy items and for males only. Among males only that subgroup without familial sinistrality demonstrated the REA. Results offer support for the following: (A) the language mechanisms involved in short-term “echoic” memory are particularly well-lateralized; (B) mechanisms underlying monaural REAs may be similar to those responsible for the asymmetries found in other paradigms; (C) processing demands and strategies inherent to the monaural technique may account in part for its limited reliability in yielding REA and for the present absence of REA among females.     

The development of children's problem solving in a gears task: A problem space perspective

I examined two contexts of development in children's problem solving: (1) the macro-context of different age cohorts (8–9 vs 11–12 years of age); and (2) the micro-context of an approximately one-hour experimental session. Twenty subjects (even divided across sexes and these two age groups) were individually presented a collection of variously sized gears, a board onto which these gears could be easily attached and rotated, and a knob. Each subject was asked to find all solutions, in which two marked gears were turning the same way, and to represent these solutions graphically. Subjects applied four different problem spaces to the task: the Euclidean, the Kinematic, the Dynamic, and the Topological. The Arithmetic Modifier could be applied to any of these problem spaces, resulting in a numerical characterization of the gear constructions and/or production strategies. The 11–12's tended to shift problem spaces adaptively; the 8–9's seldom did so. Analysis of the pathways of transition between the problem spaces revealed a complex picture of partial or complete incorporation, and substitution.