Optimal appropriateness measurement

The test-taking behavior of some examinees may be so idiosyncratic that their test scores may not be comparable to the scores of more typical examinees. Appropriateness measurement attempts to use answer patterns to recognize atypical examinees. In this report appropriateness measurement procedures are viewed as statistical tests for choosing between a null hypothesis of normal test-taking behavior and an alternative hypothesis of atypical test-taking behavior. Most powerful tests for inappropriateness are described together with methods for computing their power. A recursion greatly simplifying the calculation of optimal test statistics is described and illustrated.The work reported in this article was supported by United States Office of Naval Research contracts N00014-79C-0752, NR 154-445 and N00014-83K-0397, NR 150-518, Michael V. Levine, Principal Investigator.     

Damage to the hippocampal formation in rats selectively impairs the ability to learn cue relationships

We assessed the contribution of the hippocampal formation to performance in tasks that require rats to respond to a relationship between discriminative stimuli. The first experiment employed a nonmatching-to-sample procedure in a Y-maze. Three pairs of boxes were used which differed in brightness of the walls and in the odors that they contained. The rats were trained prior to receiving kainic acid and colchicine-induced damage to the hippocampal formation or electrolytic damage to the amygdala. After surgery all rats performed the nonmatching-to-sample task accurately if both brightness and odor cues were present in the sample and choice boxes or if the boxes contained either visual cues alone or odor cues alone. If the available cue modality was different in sample and choice boxes, then the amygdala-damaged, but not the hippocampal-damaged, rats performed accurately. In the second experiment control rats or rats with hippocampal formation damage were trained postoperatively in a conditional black/white discrimination task in a Y-maze. Only the control group successfully learned to select the white arm if the start box was illuminated and the black arm if the start box was dark. Subsequently, both groups learned a simple black/white discrimination. The same rats were tested in the hidden platform version of the Morris water task and only the control group learned to swim accurately to the goal. Both groups learned to swim accurately to a visible black platform. The results are consistent with the notion that the hippocampal formation is essential to learning that involves control exerted by a configural relationship among cues, independently of the spatial or conditional requirements of tasks.     

The Impact of A Discredited Key Witness

An experiment was conducted in order to assess the impact of discredited testimony presented by a key witness in a court setting. One of two videotaped cases was presented to subjects who were asked to assume the role of jurors and to make judgments as to the defendant's liability on the basis of the evidence presented. The three possible effects of discredited testimony on judgments were examined: logic, overcorrection, and perseverance. Subjects dealt with discredited testimony logically, ignoring it, except in one version of one of the cases where the witness' discredited testimony constituted a false accusation. In this version, subjects overcorrected in their judgments.     

What triggers causal attributions? The impact of valence and subjective probability

Various field studies and experimental simulations demonstrated that causal reasoning increases after unexpected as well as after unpleasant events. However, unpleasant events are seen as less likely than pleasant ones in everyday life. Accordingly, the subjective probability of the event and its hedonic quality were naturally confounded in these studies. To isolate the contribution of both determinants, the subjective probability and the valence of an event were independently manipulated in a laboratory experiment. Subjects completed an ostensible ‘professional skills test’ and received either success or failure feedback in relation to a criterion set by the experimenter. The subjective probability of success was varied by informing subjects about the distribution of success and failure in a comparable population (either 23 per cent or 77 per cent were said to meet the criterion). The results indicate a pronounced valence effect: The intensity of causal reasoning and the number of possible reasons reported for the outcome was greater after negative than after positive feedback, independent of the a priori probability of the outcome. No evidence for an increase in causal explanations after unexpected, as compared to expected, events was obtained. Several mediating processes are discussed.     

The effect of an integration program on teacher and student attitudes to mentally-handicapped children

This study examines the effect of contact with autistic children on teacher and peer attitudes to mentally-handicapped children in general. Children were interviewed and teachers completed questionnaires about their attitudes toward mentally-handicapped children in five schools attended by autistic boys and five schools not attended by any mentally-handicapped children. Children who had contact with autistic boys had more positive and realistic attitudes. Teachers' attitudes were generally positive and did not vary across settings, but those with experience in teaching mentally-handicapped children were found to have more positive attitudes than those with no experience. The implications for the integration of mentally-handicapped children are briefly discussed.     

Influences of metamemory on performance predictions for text

When predicting future performance on tests over text material, do individuals estimate retention in addition to assessing comprehension? In Experiment 1, participants either rated their comprehension or predicted performance for each text, with lower ratings indicating lower confidence either in comprehension or in eventual performance. Judgement magnitude was significantly lower for performance predictions than for comprehension ratings, suggesting that predictions were based partly on retention estimates. In Experiment 2, predictions varied with anticipated test delay (15 min or 2 weeks) whereas comprehension ratings did not, providing further evidence that individuals estimate retention when predicting performance. Analyses of individual differences suggest that both good and poor performers incorporate retention estimates when predicting performance, but better performers do so in a more discriminative manner. Implications for theory of metacognitive judgements are discussed.     

Higher-Order Contingentism,Part 2: Patterns of Indistinguishability

The models of contingency in what propositions, properties and relations there are developed in Part 1 are related to models of contingency in what propositions there are due to Robert Stalnaker. It is shown that some but not all of the classes of models of Part 1 agree with Stalnaker’s models concerning the patterns of contingency in what propositions there are they admit. Further structural connections between the two kinds of models are explored.