Alternative theories of concept identification among older adults

The purpose of the present experiment was to investigate some predictions of hypothesis testing and S-R association (frequency) theories regarding memory for intratrial events on a conjunctive concept-identification task. They have received extensive study with young adults but not with older subjects. The individual events under investigation were feedback, responses, hypotheses, and stimuli. Hypothesis-testing theory requires subjects to retain information concerning the correct hypothesis from one trial to the next whereas frequency does not. 75 subjects (60-70 yr. old) participated in the study. Subjects had difficulty in recalling the correct hypothesis stated on previous trials. These errors occurred on problems with negative response trials, not with incorrect feedback. The results contradict predictions based on hypothesis-testing models but are consistent with frequency theory. Unlike in the studies based on younger adults, present subjects did not recall the hypothesis very well under the conditions in which hypothesis testing was made part of the primary task.     

Evaluation of hypotheses in concept identification

The aim of this paper is to investigate the nature of hypothesis evaluation in conceptual tasks, especially in the identification of bidimensional concepts. In such tasks, hypothesis testing is seen as being composed of sampling and evaluation stages. With complex problems only one hypothesis seems likely to be sampled on each trial, and it is suggested that this hypothesis is evaluated according to a statistical decision-making process. In Experiment I, Ss were given an initial hypothesis involving one of eight rules and required to test it in an attempt to find a concept. When this given hypothesis was true (i.e., the concept), no difference was found between rules for the number of instances selected to the criterion of solution. Moreover, there was a tendency for Ss to choose instances which were predicted to be positive according to the hypothesis under test. Experiment II examined the role of memory in hypothesis testing. Immediate recall of instances selected revealed no difference between true and false hypotheses. Both primacy and recency effects were evident in recall. The number of instances correctly recalled was more than expected by models of hypothesis sampling and evaluation, and this was attributed to Ss having a low criterion for recall without intrusions. Examination of intrusions suggested that Ss may have retained some, but not all, of the features of the stimuli selected. Some differences were found between rules and between positive and netative instances on recall. These effects were suggested to be due to different amounts of information processing when classifying each type of instance for each rule; the results of Experiment III supported this suggestion.     

Slow alpha in the EEG power spectrum as an indicator for conceptual arousal]

Based on previous findings (B?sel et al., 1990) it was assumed that in concept learning tasks generating on hypotheses on a concept which has to be developed is accompanied by increases of the Alpha 1 power (7.5-10 Hz) in the spontaneous EEG activity. In this study 16 subjects performed five problem solving tasks with similar processing requirements. EEG data were analyzed by means of post hoc comparisons of subjects differing in performance quality. Additionally, four control tasks were employed in which, based on previous studies, variations in the Theta frequency range were expected. An effect in the Alpha 1 frequency band was observed in tasks requiring reconstructive recall or testing the usefulness of an mathematical algorithm. The creation of a rank order or mental map is accompanied by power increases in the lower portions of the Alpha 1 frequency band (7.5-8.5 Hz). Moreover a high amount of controlled variance (eta2 up to 34%) was obtained for this effect. Increases in EEG Theta power, which presumably indicate subjects' component analysis, were found before the subjects recognized parts of geometric figures or before relevant features in the "buddhist monk problem" were discriminated. The dynamics of EEG power over time is in examples of frequency/time plots in a figure, illustrated.     

Decision Making Versus Decision Implementation: An Action Control Approach to Exercise Adoption and Adherence1

Two studies were conducted, one involving adoption of an exercise program and the other involving adherence to an aerobics exercise program. Consistent with action control theory, it was hypothesized that (a) subjective expected utility theory would predict exercise intentions but not exercise behavior in each study; (b) exercise adoption (Study 1) and attendance at an aerobics class (Study 2) would be predictable from the intentions regarding these behaviors expressed by action-oriented but not state-oriented subjects; and (c) subjects who had engaged in planning in regard to exercising would be more likely to adopt an exercise program (Study 1) and would exercise more frequently (Study 2). The findings provide some support for all three hypotheses. Implications of this research are discussed in regard to the distinction between decision making and decision implementation or action control; the relative usefulness of an action-control versus an expectancy-value approach for behavior involving complex decision implementation over a long period of time; the value of action orientation as a moderator of intention-behavior relationships; and the role of planning in exercise behavior.     

Sources of difficulty in deductive reasoning: The THOG task

The THOG task presents four designs constructed from two shapes and two colours. Subjects are told that the experimenter has written down one of the shapes and one of the colours and are provided the rule that if, and only if, any design has either the shape or the colour, but not both, written down, then it is a THOG. Finally, they are given an exemplar and are asked to classify the remaining designs. Successful solution requires construction of hypotheses, reasoning under each hypothesis, and comparison of the results under each to reach a final conclusion. Few subjects are able to provide adequate responses on the standard version of the task. We present the results of four experiments, with 160 undergraduates each presented with one of eight versions of the task. Experiments 1 and 2 indicate that (1) some subjects think that the properties that are written down are identical to those of the exemplar, although these are not the same subjects who exhibit the modal error pattern, (2) many subjects correctly understand the disjunction of the rule but fail to consider the hypotheses, and (3) poor initial encoding of the problem is not easily corrected. Experiment 3 investigates the sufficiency of the claim of Griggs and Newstead (1982) that appropriate problem solution follows from explicit presentation of all problem information (including use of positive labels for properties that are not written down), and Experiment 4 investigates the necessity of the claim. The results of Experiments 3 and 4 show that presenting positive category labels does increase the frequency of correct solution; however, positive category labels are not necessary for such improvement. Separation of the labels of the THOG rule from those of the exemplar, or informing subjects that only one other design is a THOG, also increases the frequency of successful solution. The results suggest that many people have some fairly sophisticated reasoning skills. but application of these skills is easily discouraged when the features of the task lead to poor initial encoding.     

Effect of cue validity on learning of complex rules in probabilistic inference tasks

The effect of cue validity on the learning of positive and negative J-shaped relations in single-cue probability learning was studied. As would be expected from a hypothesis construction model, learning of the J-shaped relations was better when cue validity was high than when it was low. However, the results also showed that positive J-rules were learned more efficiently than negative J-rules. This shows that subjects do not construct their hypotheses on the basis of data from task only. It was concluded that subjects construct their hypotheses from elements stored in memory, and that data are used only to test their hypotheses.     

Concept Discovery in a Scientific Domain

The scientific reasoning strategies used to discover a new concept in a scientific domain were investigated in two studies. An innovative task in which subjects discover new concepts in molecular biology was used. This task was based upon one set of experiments that Jacob and Monod used to discover how genes are controlled, and for which they were awarded the Nobel prize. In the two studies reported in this article, subjects were taught some basic facts and experimental techniques in molecular biology, using a simulated molecular genetics laboratory on a computer. Following their initial training, they were then asked to discover how genes are controlled by other genes. In Study 1, subjects found no evidence that was consistent with their initial hypothesis. Subjects then set one of two goals for conducting experiments and evaluating data. One goal was to search for evidence consistent with the current hypothesis (and they did not attend to the features of discrepant findings); none of the subjects who only had this goal succeeded at discovering how the genes were controlled. Other subjects in Study 1 used a different goal: Upon noticing evidence inconsistent with their current hypothesis, these subjects set a new goal of attempting to explain the cause of the discrepant findings. Using this goal, a subset of these subjects discovered the correct solution to the problem. Study 2 was conducted to test the hypothesis that subjects' goals of finding evidence consistent with their current hypothesis blocks consideration of alternate hypotheses and generation of new goals, it was predicted that if subjects could achieve their initial goal of discovering evidence consistent with their current hypothesis, they would then attend to particular features of discrepant evidence and solve the problem. To test this prediction, an additional mechanism of genetic control that was consistent with subjects' initial goal was added to the genes. Here, subjects had to discover two mechanisms of control: one mechanism consistent with their current hypothesis, and one inconsistent with their hypothesis. Twice as many subjects reached the correct solution in Study 2 than in Study 1. The findings of the two studies indicate that goals provide a powerful constraint on the cognitive processes underlying scientific reasoning and that the types of goals that are represented determine many of the reasoning errors that subjects make.     

Shared and unique prototype features of relationship quality concepts

Previous research on relationship quality concepts suggests they are not as distinct as expected. What aspects are similar and distinct across these concepts? Using a prototype approach, this research identified the commonalities and uniqueness of 7 relationship quality concepts: commitment, intimacy, love, passion, satisfaction, trust, and relationship quality. The results indicated that (a) 4 features were shared across all 7 concepts, and some were exclusive to each concept, and (b) shared features were rated as more important for romantic relationship functioning than unique features both explicitly and implicitly. This research provides a framework to understand overarching and distinct aspects of relationship quality concepts and how this is reflected in people's evaluation of what is important in romantic relationships.     

Implicit Learning and Concept Learning

In Experiments 1 and 2, subjects were exposed to letter strings that followed a pattern—the second letter was always the same. This exposure was disguised as a test of immediate memory. Following this training, subjects could discriminate new letter strings following the pattern from letter strings not following the pattern more often than would be expected by chance, which is the traditional evidence for concept learning. Discrimination was also better than would be predicted from subjects' explicit report of the pattern, demonstrating the co-occurrence of concept learning and implicit learning. In Experiment 3, rules were learned explicitly. Discrimination was worse than would be predicted from subjects' explicit report, validating the implicit learning paradigm. In Experiment 4, deviations from a prototypical pattern were presented during training. In the test of discrimination, prototypes were as familiar as old deviations and more familiar than new deviations, even when considering only implicit knowledge. Experiment 5 found implicit knowledge of a familiar concept. These results are consistent with the hypothesis that the distinguishing features of a concept can be learned implicitly, and that one type of implicit learning is concept learning.     

Testing specificity and guidance hypotheses by manipulating relative frequency of KR scheduling in motor skill acquisition.

This investigation tested predictions of specificity and guidance hypotheses by manipulating relative frequency of knowledge of results scheduling using a shuffleboard task. Participants were assigned to either a 100%-KR, three 50%-KR conditions (Constant, Fade, Reverse), or 00%-KR condition. Based on predictions of the specificity hypothesis, it was expected the 00%-KR condition would perform the best on a no-KR retention test. It was also expected the 100%-KR condition would perform poorly on a no-KR retention test based on predictions of the guidance hypothesis. Analysis for 55 men's and 55 women's retention did not support predictions of the specificity hypothesis and provided partial support for the guidance hypothesis.     

A Prototype Matching Approach to Understanding the Role of Applicant Gender and Age in the Evaluation of Job Applicants1

This research uses a prototype matching approach to understand how job applicant evaluations are made and the role that applicant gender and age play in these evaluations. It is hypothesized that raters represent information about jobs and jobholders in person-in-job prototypes. Raters evaluate applicants by matching information about applicants to the person-in-job prototype associated with the job for which the applicant is applying. Person-in-job prototypes are comprised of features that are more (i.e., central) or less (i.e., peripheral) strongly associated with the prototype. Three laboratory studies examined several hypotheses derived from a prototype matching approach. Results indicated that applicants who matched on more central features were evaluated more favorably than applicants who matched on fewer central features of person-in-job prototypes. In addition, applicants who matched on age were evaluated more favorably than applicants who did not match on age when age was a central but not a peripheral feature of a person-in-job prototype. However, applicants who matched on gender were not evaluated differently from applicants who did not match on gender when gender was a central or a peripheral feature of a person-in-job prototype. Finally, there was some evidence that raters used applicant gender in a complex manner when evaluating applicants. Implications for theory and research on bias in selection are discussed.     

Generalization hypothesis of abstract-concept learning: learning strategies and related issues in Macaca mulatta, Cebus apella, and Columba livia

The generalization hypothesis of abstract-concept learning was tested with a meta-analysis of rhesus monkeys (Macaca mulatta), capuchin monkeys (Cebus apella), and pigeons (Columba livia) learning a same/different (S/D) task with expanding training sets. The generalization hypothesis states that as the number of training items increases, generalization from the training pairs will increase and could explain the subjects' accurate novel-stimulus transfer. By contrast, concept learning is learning the relationship between each pair of items; with more training items subjects learn more exemplars of the rule and transfer better. Having to learn the stimulus pairs (the generalization hypothesis) would require more training as the set size increases, whereas learning the concept might require less training because subjects would be learning an abstract rule. The results strongly support concept or rule learning despite severely relaxing the generalization-hypothesis parameters. Thus, generalization was not a factor in the transfer from these experiments, adding to the evidence that these subjects were learning the S/D abstract concept.     

An hypothesis generation model for judgment in nonmetric multiple-cue probability learning

The purpose of this paper is to present a two-phase hypothesis generation model to describe behavior in multiple-cue probability learning tasks with nonmetric cues. The model assumes that on each trial the subject generates two sets of hypotheses: (a) a hypothesis concerning which cue dimension (or pattern) will lead to a correct prediction on that trial and (b) a hypothesis concerning which response will be correct given the cue dimension attended to on that trial.Five-hundred-twelve subjects were assigned to 20 groups in a binary choice task involving two binary cue dimensions. Each group observed cues which differed in validity. Analysis of the data indicated that subjects attend to both cue dimensions in making judgments even when one cue has zero validity. A test of the fit of the observed data to the asymptotic response proportions predicted by the model indicated a reasonable fit.     

Learned helplessness and judgments of control

One of the central hypotheses of learned helplessness theory is that exposure to noncontingency produces a reduced ability to perceive response-outcome relations (the postulated "cognitive deficit"). To test this hypothesis, subjects were exposed to a typical helplessness induction task and then asked to make judgments of the amount of control their responses exerted over a designated outcome (the onset of a light). Support for the postulated cognitive deficit would be found if subjects who experienced the induction underestimated the relation between their responses and outcomes. The results, however, demonstrated that induction subjects (n = 30) made higher and more accurate judgments of control than subjects in a no-treatment control group (n = 30). This finding clearly fails to support the postulated cognitive deficit and highlights the need for other direct tests of the basic hypotheses of helplessness theory.     

Effectiveness of Positive Hypothesis Testing in Inductive and Deductive Rule Learning

In a positive hypothesis test a person generates or examines evidence that is expected to have the property of interest if the hypothesis is correct, whereas in a negative hypothesis test a person generates or examines evidence that is not expected to have the property of interest if the hypothesis is correct. Two experiments assessed the effectiveness of positive versus negative hypothesis tests on inductive and deductive rule learning problems. In Experiment 1 problem solvers induced a rule by proposing hypotheses and selecting evidence in the eight conditions of a factorial design defined by instructions to use a positive or negative hypothesis test on each of trials 1-5, 6-10, and 11-15. Instructions to use positive tests resulted in more examples, fewer strategic hypotheses, and a higher weighted score for five types of hypotheses than instructions to use negative tests. In Experiment 2 problem solvers identified 1 of a possible 1296 correct rules in the deductive rule learning game Mastermind. When problems were classified in the 16 possible combinations of positive or negative hypothesis tests on trials 2, 3, 4, and 5 there were fewer trials to solution for positive tests on each of the four trials and fewer trials to solution with increasing positive tests. We conclude that positive hypothesis tests are generally more effective than negative hypothesis tests in both inductive and deductive rule learning. Copyright 1999 Academic Press.     

Adapting chronometric tests for field studies of cognitive ability

This study was designed to examine the relationship of hand preference to performance on a thumb-positioning task. Two hypotheses were proposed on the basis of hemispheric lateralization. The first stated that all subjects would perform the task more accurately using the left thumb, regardless of hand preference. The second hypothesis tested was that left-handed subjects would perform more accurately than right-handed subjects. Each of 20 neurologically intact adults grouped by hand preference reproduced a criterion thumb position with both thumbs simultaneously. Absolute error, recorded for each movement and analyzed by mixed analysis of variance, did support the first hypothesis. However, the left-handed group did not perform statistically differently from right-handed subjects. Factors influencing the data are discussed and recommendations for further studies are made.     

The attributional response of males and females to noncontingent feedback

The attributions of male and female college student subjects following exposure to noncontingent, contingent, and no-feedback conditions were analyzed in a 2×3 multivariate analysis of variance. The experimental hypothesis was that exposure to noncontingent feedback would result in more depressive attributions than exposure to contingent feedback or to no feedback, and that this effect would be moderated by gender. The hypothesis was partially supported in that females receiving noncontingent feedback on a concept discrimination problem subsequently made more internal attributions for negative events than male subjects receiving noncontingent feedback and female subjects receiving contingent feedback or no feedback.     

Prototypes and personal templates: collective wisdom and individual differences

This article concerns individual differences in the associative meaning of psychological concepts. Associative meaning may be assessed with prototype methodology, which yields a list of features of the concept ordered according to their rated importance. Our theory concerns individual differences in a concept's associative meaning: A personal template reveals a person's idiosyncratic associative meaning. It is possible to assess the degree to which a personal template matches the corresponding prototype. The theory distinguishes among three types of concepts. One type, for example, specifies a particular behavior to be predicted, for example, a person who is likely to commit suicide, and features of the prototype would include predictors of suicidal behavior. According to the theory, the most prototypical features are (under specifiable conditions) valid predictors, and people with a strong template-to-prototype match possess more valid knowledge about the concept than do people with a weak template-to-prototype match. Other types of concepts cannot be validated (e.g., those describing subjective experiences). In that case, a strong template-to-prototype match does not reflect a person's degree of valid knowledge. The authors provide three applications of the theory.