Positive and Negative Hypothesis Testing by Cooperative Groups

In a rule induction problem positive hypothesis tests select evidence that the tester expects to be an example of the correct rule if the hypothesis is correct, whereas negative hypothesis tests select evidence that the tester expects to be a nonexample if the hypothesis is correct. Previous research indicates the general effectiveness of a positive test strategy for individuals, but there has been very little research with cooperative groups. We extend the analysis of Klayman and Ha (Psychological Review, 1987) of ambiguous verification or conclusive falsification of five possible types of hypotheses by positive and negative tests by emphasizing the importance of further examples following hypothesis tests. In two experiments four-person cooperative groups solved rule induction problems by proposing a hypothesis and selecting evidence to test the hypothesis on each of four arrays on each trial. In different conditions the groups were instructed to use different combinations of positive and negative tests on the four arrays. Positive tests were more likely to lead to further examples than negative tests, and the proportion of correct hypotheses corresponded to the proportion of positive tests, in both experiments. We suggest that positive tests are more effective than negative hypothesis tests in generating further evidence, and thus in inducing the correct rule, in experimental rule induction tasks with a criterion of certainty imposed by the researcher.     

Promoting the Culturally Sensitive Diagnosis of Mexican Americans: Some Personal Insights

This article presents a series of personal guidelines for promoting the culturally sensitive psychiatric diagnosis of Mexican American/Chicano clients. These guidelines are primarily based on the authors' collective experiences in diagnosing and treating this population.     

SEEING TWO AS ONE:

Abstract -Object tokens are episodic visual representations that mediate the ability to track visual events as they move about and change over time. Multiple tokens also allow the viewer to individuate multiple instances of a single type of object. In the present study, we established a functional link for object tokens in two seemingly disparate visual phenomena: apparent motion and repetition blindness [RB]. In RB, repeated items are more difficult to perceive than unre-peated items. Using displays in which two sets of alphanumeric characters streamed in opposite directions across a computer screen in apparent motion, we found increased RB for targets appearing within a single apparent motion stream, relative to targets in different apparent motion streams. The results are inconsistent with refractory period or memory retrieval accounts of RB and support the role of object tokens in both apparent motion and RB.     

ASSOCIATIVE PROCESSES IN FALSE RECALL AND FALSE RECOGNITION

Abstract— Studying a list of words associated to a critical nonpresented word results in high rates of false recall and false recognition for that nonpresented item (Roediger & McDermott, 1995) Two experiments examined the effect of manipulating the number of associates presented on false recall and later false recognition of a nonpresented item. In Experiment 1, associate lists of varying lengths were studied, in Experiment 2, list length was held constant and the number of associates within the list was manipulated. In both experiments, the rate of critical intrusions in recall increased steadily with increasing number of associates studied Most notably, the filler words used in Experiment 2 to equate the list lengths did not affect the rate of critical intrusions, although they did depress recall of studied words. False recall and false recognition appear to be tied to the total, not the mean, associative strength of items in the list.     

Performance Self-Predictions: The Impact of Expectancy Strength and Incentives1

Performance self-predictions represent an individual's anticipated level performance on an upcoming task. This study focused on the accuracy of these predictions, as well as subjective reactions to making them under varying expectancy and incentive conditions. Results indicate that performance-contingent incentives had a positive effect on task performance, but a negative effect on preferences for making performance predictions. Expectancy strength also influenced these predictions, their subjective interpretations, and task performance. Additional results address the role of other task-relevant judgments (e.g., self-assessed ability and intended effort) when predicting one's performance on a task. Implications of these findings for work motivation and judgment accuracy are discussed.     

Simulation and the Reproduction of Injustice: A Reply

Melinda Vadas rejects my claim that there are morally relevant differences between simulations of unjust events and actual unjust events on the ground that I overlook the connection between simulations and that which they simulate. I argue that this purported moral connection can only be understood as either the result of a necessary psychological disposition or as a “magical,” metaphysical attachment, neither of which is defensible or satisfactory.     

Children's capacity to agree to psychological research: knowledge of risks and benefits and voluntariness

A series of studies investigated the capacity of children between the ages of 7 and 12 to give free and informed consent to participation in psychological research. Children were reasonably accurate in describing the purpose of studies, but many did not understand the possible benefits or especially the possible risks of participating. In several studies children's consent was not affected by the knowledge that their parents had given their permission or by the parents saying that they would not be upset if the children refused. In contrast, other studies found that children were much more likely to stop their participation if the experimenter said explicitly that she would not be upset if they stopped. We suggest that experimenters should pay more attention to describing the possible risks and benefits of participation in research, and that they should also make it clearer to children that they are free to stop once they have begun.     

The judgment-choice discrepancy: Noncompatibility or restructuring?

The study examines the relative merits of a noncompatibility and a restructuring explanation of the recurrent empirical finding that a prominent attribute looms larger in choices than in judgments. Pairs of equally attractive options were presented to 72 undergraduates who were assigned to six conditions in which they performed (1) only preference judgments or choices, (2) preference judgments or choices preceded by judgments of attractiveness of attribute levels, or (3) preference judgments or choices accompanied by think-aloud reports. The results replicated the prominence effect for choices, but a prominence effect was also found for preference judgments. In accordance with the restructuring explanation, the think-aloud protocols indicated that options were more often restructured in choices than in preference judgments. However, restructuring could not explain the prominence effect observed for preference judgments. A modified compatibility hypothesis is offered as an alternative explanation.     

Question-begging and infinite regress

InMetaphysics , Ch. 4, Aristotle speaks of both infinite regress and question-begging, but does not explicitly relate them. We get the impression that he thinks that to use one of these arguments to avoid the other is to jump from the frying-pan into the fire. This relationship is illustrated in terms of the ignorant belief that everything can be proved, and of attempts to prove the Law of Noncontradiction.