Lasting reductions in illegal moves following an increase in their cost: evidence from river-crossing problems

The authors present 3 experiments demonstrating ways to reduce illegal moves in problem-solving tasks. They propose a 3-stage framework for the rejection of illegal moves. An illegal move must come to mind and be selected, checked for legality, and correctly rejected. Illegal move reduction can occur at any stage. Control group participants benefited from solving the same problem twice but failed to show transfer to an isomorph, replicating results from S. K. Reed, G. W. Ernst, and R. Banerji (1974). Participants who were penalized for making illegal moves showed reductions in illegal moves even when solving a novel isomorph without penalty. The authors propose that illegal move reduction occurs when solvers are cautious and check moves for legality frequently.     

A process model for water jug problems

We develop and evaluate a model for the water jug task in which a subject is required to find a sequence of moves (pouring operations) which produce a specified amount of water in each jug. Experiment 1 was designed to evaluate the meansends, move selection heuristics that are assumed by the model. Experiment 2 tested the model's predictions concerning those aspects of the water jug task that determine problem difficulty.A three stage process model incorporating GPS-like, means-ends heuristics and assumptions concerning the utilization of short- and long-term memory was able to account for differences across problems as well as details of the performance of subjects solving a given problem. We conclude that a GPS-like model that only selects one move at a time (no forward planning of move sequences or setting up of subgoals) can provide a good account of solution behavior in the water jug task.     

Suggestions for revised scoring of the Tower of Hanoi test

Detailed time and error analyses of the Tower of Hanoi (TOH) test was performed using four repeated assessments of eight children (ages 9-12 years), who had perceptual and problem solving deficits. The time before each move was measured. In addition to the traditionally counted time scores, new, relative time scores were computed in order to separate the planning time from the general reaction speed. New error scores were defined and sum scores of serious errors (perserative moves, illegal moves, and wrong results) and mild errors (self-corrected moves, almost performed moves, and interrupted trials) were computed. The relative planning time correlated positively with the achieved score, and negatively with the serious errors. The serious errors correlated negatively with the achieved score. The relative planning time seems to measure the quality of planning better than does the raw planning time, and it is a recommended score for TOH analysis. The value of new error scores requires additional research.     

Hobbits and orcs: Acquisition of a sequential concept

Subjects solved the hobbits-orcs problem repeatedly until they made no errors on two successive solutions. Groups varied in the kind of feedback given after errors. Further support was obtained for Thomas' (this journal) conclusion that subjects organize the sequence of moves in small subsequences, rather than individual moves. Differences between feedback groups suggested that the organization is oriented forward in the problem, and this contrasts with GPS' retroactive organization of this problem. Comparison between feedback groups also leads to the conclusion that subjects learned from positive information indicating which response is correct, rather than by a process of eliminating errors or sampling new strategies after errors. Analysis of acquisition data agreed with the hypothesis of all-or-none learning at individual states, except for one state where the additional complexity was related to an ambiguity about backward moves. The general pattern of results was invariant over a change in the characters of the problem (men and elves) designed to produce a reversal of relationship between the characters concerning who was prevented from outnumbering whom.     

Developing a plan for solving a problem: A representational shift

Research analyzing transitions from lower to higher levels of problem solving has focused either on quantitative increments in processing demands (Case, 1984; Klahr & Robinson, 1981) or on qualitative shifts in the organization of representations (Fischer & Pipp, 1984; Piaget, 1976). This study is concerned with distinguishing the value of these two approaches to problem solving through a microgenetic analysis of children's initial attempts to solve the Tower of Hanoi problem. As suggested by Siegler and Crowley (1991), a microgenetic approach is particularly useful in determining the process of cognitive change. One-hundred and thirty-six children, ages 6 through 8 years, were presented with the standard three-disc problem and allowed 3 minutes to complete it. The quality of the children's performance was analyzed by noting the positioning of the first move, the number and location of illegal moves, and the frequency and location of optimal moves. The results indicate that qualitative shifts in children's representation of the problem space are a crucial aspect of successful performance.     

汉诺塔问题解决的认知过程及特点分析

以267名大学生为被试,对汉诺塔问题(Tower of Hanoi)解决的认知过程及特点进行了分析。相对于汉诺塔问题解决较差者(有多余移动步骤的被试)而言,以最少步数解决汉诺塔问题的被试其第一步计划时间较长,但平均计划时间却明显要短。汉诺塔问题解决较差者多在关键步骤上出错,从而导致多余的移动步数以及总体完成时间的延长。进一步分析表明,汉诺塔问题解决的这种认知活动主要反映的是与计划和抑制有关的总体计划协调能力以及空间短时记忆能力。     

Working in Dyads and Alone: Examining Process Variables in Solving Insight Problems

This study investigated the effects of working in dyads and their associated gender composition on performance (solution rate and time) and process variables (number of impasses, number of passed solutions, and number of problem solving suggestions and interactions) in a set of classic insight problem solving tasks. Two types of insight problems were used: multiple moves available (MMA) and few moves available (FMA) problems. The results showed no effects on number of problems solved or solving time, but group and gender composition effects emerged when looking at process variables such as number of impasses, time to impasse, number of passed solutions, number of problem solving suggestions, and number of interactions between dyad members. Results support prior evidence that process loss in creative problem solving may be due to differences in interpersonal interactions during group problem solving that do not necessarily affect overall problem solving success.     

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.     

Phonological processes and the perception of phonotactically illegal consonant clusters

The perception of consonant clusters that are phonotactically illegal word initially in English (e.g., /tl/, /sr/) was investigated to determine whether listeners’ phonological knowledge of the language influences speech processing. Experiment 1 examined whether the phonotactic context effect (Massaro & Cohen, 1983), a bias toward hearing illegal sequences (e.g., /tl/) as legal (e.g., /tr/), is more likely due to knowledge of the legal phoneme combinations in English or to a frequency effect. In Experiment 2, Experiment 1 was repeated with the clusters occurring word medially to assess whether phonotactic rules of syllabification modulate the phonotactic effect. Experiment 3 examined whether vowel epenthesis, another phonological process, might also affect listeners’ perception of illegal sequences as legal by biasing them to hear a vowel between the consonants of the cluster (e.g., /talee/). Results suggest that knowledge of the phonotactically permissible sequences in English can affect phoneme processing in multiple ways.     

Preference for modes of dispute resolution as a function of process and decision control

Research on procedural justice has suggested that the distribution of control among participants can be used to classify dispute-resolution procedures and may be an important determinant of preference for such procedures. This experiment demonstrates that control can be meaningfully divided into two components: control over the presentation of evidence and control over the final decision. The experiment placed subjects (law students and undergraduates) in a situation of conflict and varied two between-subjects factors: (1) Role, whether subjects expected to role-play third parties (law students) or litigants (undergraduates), and (2) Orientation, whether individuals focused on equity claims (appeals to a norm of fairness) or legal claims (appeals to a strict, legal interpretation of events). As a control, a third-party neutral-orientation condition was included. In addition, subjects were presented with four dispute-resolution procedures which varied in third-party control over the presentation of evidence (Process Control) and third-party control over the final decision (Decision Control) as within-subjects factors. Results revealed that both litigants and third parties preferred high rather than low third-party decision control. Litigants with an equity orientation preferred low third-party control over the presentation of evidence, particularly when third parties had high rather than low decision control. Third parties and litigants with a legal orientation preferred low rather than high third-party process control only when there was high third-party decision control. Litigant preferences were more affected by variation in process control than variation in decision control while third-party preferences were more affected by variation in decision control than in process control. As a check on external validity, military judges given a neutral orientation were asked to evaluate and express preferences for the four dispute-resolution procedures. Their results were not detectably different from those of the law students who role-played third parties in the main portion of the study.     

Are morphological structures computed during word recognition?

In the recent literature in generative morphology, it has been assumed that multimorphemic words must be characterized as having a hierarchical internal structure which is expressible in the form of morphological trees. This paper reports on an experiment which addresses the following question: Are these structures relevant to complex word recognition? In a naming latency experiment, subjects were presented with prefixed and suffixed nonsense roots. The use of stimuli such as these allowed for the control of real word effects such as frequency and semantic plausibility and made it possible to systematically vary the configuration of the morphological trees. Significant response time differences were found between the morphologically illegal forms and legal configurations. This was taken as evidence that subjects do compute morphological representations. Because no differences were found between legal left-branching structures and legal right-branching structures, it was concluded that morphological computation is not sensitive to the serial ordering of morphemes within a complex word.     

Testing an Integrated Model of Advice Giving in Supportive Interactions

Viewing supportive communication as a multistage process, the present study proposed and tested an integrated model of advice giving, which specifies three sequential moves in supportive interactions involving advice: emotional support, problem inquiry and analysis, and advice. Seven hundred and fifty‐two participants read and responded to a hypothetical scenario in which they received advice from a friend. Results of the study showed that advice that was offered following the moves of emotional support and problem inquiry and analysis was judged to be higher in quality than advice that did not follow this sequential pattern.     

The influence of verbalization on problem-solving

The performance of subjects who were required to state reasons for moves while solving the Tower-of-Hanoi problem was compared to the performance of subjects who were not required to do so. In accordance with previous research it was found that stating reasons facilitated performance in reducing superfluous moves (errors). In addition it was found that the effect was due to a significant decrease in errors for moves close to important subgoals in a goal hierarchy of moves. The effect was explained in terms of the replacement of an automated process with controlled calculations for moves close to subgoals.     

Move evaluationasa predictor and moderator of success in solutions to well-structured problems

This paper presents three studies concerned with the evaluation of moves in solutions to Tower of Hanoi problems and the effect that such evaluation processes have on solution success. The existing literature on problem solving suggests that verbalizing whilst solving a problemcan havea positive effect upon performance. However,such verbalization has to be directed toward an explicit evaluation of particular moves. What remains unclear is whether evaluation without verbalization has the same effects or whether some characteristic of the process of verbalization gives rise to improved performance on such tasks. For example, the act of verbalizing per se may simply mean that more processing time is directed toward the problem-solving process. The studies reported in this paper suggest that the process of evaluation may be independent of verbalization processes and that non-verbal evaluation of moves (indicated by a key press) produces the same effects as a verbal evaluation of such moves. Moreover, the process of evaluating moves appears to producea form of behaviour that is prone to disruption via the administration of secondary tasks, whereas non-evaluated solutions are not. This may suggest that problem solvers who engage in evaluation processes develop an explicit representation of the strategies used to solve the problem.     

Problem-Solving Restructuration: Elimination of Implicit Constraints

A general model of problem-solving processes based on misconception elimination is presented to simulate both impasses and solving processes. The model operates on goal-related rules and a set of constraint rules in the form of “if (state or goal), do not (Action)” for the explicit constraints in the instructions and the implicit constraints that come from misconceptions of legal moves. When impasses occur, a constraint elimination mechanism is applied. Because successive eliminations of implicit constraints enlarge the problem space and have an effect on planning, the model integrates “plan-based” and “constraint-based” approaches to problem-solving behavior. Simulating individual protocols of Tower of Hanoi situations shows that the model, which has a proper set of constraints, predicts a single move with no alternative on about 61% of the movements and that protocols are quite successfully simulated movement by movement. Finally, it is shown that many features of previous models are embedded in the constraint elimination model.     

A comparison of the other-directed stigmatization produced by legal and illegal forms of affirmative action

Recent studies have begun to show that the stigma of incompetence sometimes directed toward the beneficiaries of affirmative action may be significantly reduced as the preferences granted to women and minorities become more moderate. The author examined whether the stigmatization of African Americans would differ under hiring policies that represented legal and illegal levels of racial preference according to federal regulations. Participants were 178 students and 161 corporate employees who rated fictitious Black and White target employees working under (a) an illegal policy of selection of unequal candidates, (b) a legal policy of selection of comparable candidates, or (c) equal opportunity. Participants rated Black targets' achievement-related traits lower than White targets only under the illegal policy. Under the legal policy, no such stigmatization was observed. Additional dependent measures and theoretical implications were explored.     

Typing letter strings varying in orthographic structure

Subjects typed six-letter strings varying in orthographic structure. Lexical status, word frequency, position-sensitive log bigram frequency, and regularity of letter sequencing were systematically varied. Cumulative reaction times (RTs) of the keystrokes were adequately described by a linear function of letter position in the test string. Overall, words were typed faster than nonwords, and regular strings faster than irregular strings. Although the effect of log bigram frequency was not significant, this variable interacted with regularity and word frequency. Post hoc analyses of performance on each of the 200 letter strings revealed significant effects of the number of irregularities, log bigram frequency, and log word frequency. Transition times between successive keystrokes were significantly longer for illegal than for legal letter transitions. These results are similar to previous findings on the role of orthographic structure in the perceptual recognition of letter strings and provide a more complete analysis of context effects in typing.     

The role of analogy in transfer between similar problem states

The study investigated the effect of transfer between two problems having similar (homomorphic) problem states. The results of three experiments revealed that although transfer occurred between repetition of the same problems, transfer occurred between the Jealous Husbands problem and the Missionary—Cannibal problem only when (a) Ss were told the relationship between the two problems and (b) the Jealous Husbands problem was given first. The results are related to the formal structure of the problem space and to alternative explanations of the use of analogy in problem solving. These include memory for individual moves, memory for general strategies, and practice in applying operators.     

小学儿童对日常生活事件时间关系推理能力的初探

探查小学儿童对含有“在什么之前”“同时”日常生活事件时间关系的推理发展过程及其影响因素。被试为7岁、9岁、11岁3个年龄组共54名小学儿童,每个年龄组18人。4种问题模式分别为带有传递关系的单模型问题、带有无关前提的单模型问题、含两个前提的单模型问题、有肯定答案的多模型问题。每种问题模式含3种具体探察任务。主要研究结果表明：在本实验条件下,（1）儿童对事件时间顺序关系的推理从7岁到9岁有快速发展的趋势;（2）单模型和多模型任务无显著差异,模型数量似乎不是影响儿童推理成绩的关键因素;（3）儿童能够主动采用5种策略解决问题。逆向关系传递策略是问题解决的有效策略。     

Building phonotactic knowledge in bilinguals: role of early exposure

Timing and amount of exposure to a 2nd language in the acquisition of phonotactic restrictions was examined in 4 experiments. In Experiments 1 and 2, 10-month-old monolingual and bilingual Catalan-Spanish infants were presented with nonwords that were phonotactically legal or illegal in Catalan and phonotactically illegal in Spanish. Differences between the 4 groups of infants were obtained as a function of language dominance. In Experiments 3 and 4, adult Spanish-Catalan bilinguals were compared with the same materials. Catalan-dominant bilinguals were more accurate than Spanish-dominant bilinguals in their perception of legal sequences; however, they were not more accurate with illegal sequences. The findings suggest a complex correlation between the pattern of preference and the amount and timing of exposure.