Kooperatives Lernen auf der Grundlage komplementären Vorwissens: ein Experiment und eine Simulationsstudie

Summary. Knowledge acquisition in collaborative problem solving is mainly realized by two activities: (1) when participants mutually impart their knowledge and (2) when they elaborate their knowledge together. Both activities are favoured by differences in the participants' prior knowledge. To support this thesis, an experimental study and a cognitive simulation are described. In the study, pairs of students were systematically taught complementary knowledge about qualitative resp. quantitative aspects of classical mechanics. During the subsequent collaborative problem solving the students successfully exchanged information about their complementary knowledge. Students who had been taught knowledge about qualitative aspects of physics gained more from their partners than students who had been taught knowledge about quantitative aspects. A cognitive model simulates problem solving and learning under the conditions set up in the study. In a simulation study based on the cognitive model it was possible to reconstruct the main results of the experimental study. Finally, the role of dialogue analysis and external representations are discussed and conclusions for the design of computer systems supporting collaborative problem solving are drawn. Zusammenfassung. Wissenserwerb bei der Kooperation vollzieht sich vor allem durch zwei Aktivitäten: (1) gegenseitige Wissensvermittlung und (2) gemeinsame Elaboration des Wissens. Für beides ist unterschiedliches Vorwissen der Beteiligten eine günstige Voraussetzung. Um diese These zu unterstützen, wird im vorliegenden Artikel eine experimentelle Studie dargestellt, in der Paaren von Schülerinnen systematisch komplementäres Vorwissen über qualitative bzw. quantitative Aspekte der klassischen Mechanik vermittelt wurde. Beim anschließenden kooperativen Problemlösen vermittelten die Schülerinnen sich gegenseitig erfolgreich Teile ihres Wissens. Schülerinnen, die zuvor Wissen über qualitative Aspekte der Physik erworben hatten, lernten dabei mehr von ihren Partnerinnen als Schülerinnen, die zuvor Wissen über quantitative Aspekte erworben hatten. Ein nachfolgend implementiertes kognitives Modell simuliert kooperatives Lernen und Problemlösen unter den Bedingungen der Studie und ist in der Lage, die zentralen Befunde der Studie zu rekonstruieren. In der Diskussion wird auf die Rolle des Dialogverhaltens und der Nutzung externer Repräsentationen für das kooperative Lernen und Problemlösen eingegangen. Abschließend werden Schlußfolgerungen für die Gestaltung von Computersystemen zur Unterstützung kooperativen Lernens und Problemlösens gezogen.     

Krankheitsbewältigung und Überlebenszeit bei Krebskranken

Although a considerable number of studies have addressed the question whether cancer patients’ coping with the disease is a predictor of survival, this issue is still controversely discussed. In the present paper, the previous research on the relationship between coping and survival is reviewed. Whereas some evidence has been produced that active coping is linked with longer survival, results regarding the significance of denial proved inconclusive. However, some researchers demonstrated that emotional distress was predictive of shorter survival, while still others found that the expression of distress predicted a better outcome. Thus, the available data are inconclusive. Moreover, most studies suffered from methodological limitations such as retrospective design, multiple testings, small sample size, heterogeneous sample constitution, unproven assessment instruments, inadequate control for biological prognostic factors, and inadequate statistical analysis. The results of a hypotheses-guided, prospective study with 103 lung cancer patients are presented. Patients were assessed before primary treatment began (inception cohort), using both self-reports and interviewer ratings. After a follow-up of 7 to 8 years, the interviewer rating of active coping predicted a longer survival, and both self and interviewer ratings of depressive coping were predictive of a shorter survival, when entered as continuous variables into a Cox regression model adjusting for biomedical risk factors such as tumor stage, histological classification and Karnofsky performance status. Among the possible mechanisms explaining this relationship are the reactions of the patients to the physical burden of cancer that might be better reflected in subjective measures such as the well-being and quality of life ratings compared with the cruder biomedical classifications, as well as psychoneuroimmunological pathways which, however, to a substantial part remain hypothetical by now, and the compliance with treatment. Further research must engage in experimental studies to clarify the causal relation between coping and survival among patients with cancer.     

Left anterior lobectomy and category-specific naming

Damasio and colleagues (1996) have proposed that the left anterior temporal region supports knowledge pertaining to living objects, whereas more posterior temporal regions play a critical role in naming nonliving things. Accordingly, one might expect that left-sided anterior temporal lobectomy should have a more profound effect on the naming of living as opposed to nonliving things. As part of a multicenter collaborative project, seventy-nine patients (all left-hemisphere speech dominant) were tested pre- and post-left-temporal lobectomy on a task that required naming of living and nonliving items equated for name frequency, familiarity, and visual complexity. Consistent with the proposals of Damasio et al. (1996), left temporal lobectomy impaired naming ability, particularly for living things. When individual outcomes were considered, twice as many patients showed a relative decline in naming living as opposed to nonliving things.     

Psychosocial and organic variables as predictors of lung cancer,cardiac infarct and apoplexy: Some differential predictors

In a longitudinal study started in 1965 in Crvenka (Yugoslavia), a number of psychosocial and organic variables were measured in 1353 Ss and related to the incidence of cancer, circulatory and other diseases in the subsequent 10-yr period by multivariate statistical methods. The present article reports on an attempt at differential prediction of lung cancer and cardiac infarct or apoplexy, which were selected because smoking is usually held to be a common risk factor for them. In a discriminant analysis (minimizing the overall classification error), 86–87% of the lung cancer and infarct/apoplexy cases could be predicted correctly, as well as 97% of the cases showing neither of the diseases. Some psychosocial variables like rationality and anti-emotionality or long-lasting hopelessness were about as relevant as the strongest organic predictors like level and variability of blood cholesterol.     

Psychopathology in epilepsy. The role of psychology in altering paradigms of research, treatment, and prevention.

This article offers a brief review of the literature examining epilepsy and abnormal behavior. The generally accepted concept of epilepsy as a high psychiatric risk disorder is reexamined in light of research that has investigated the influence of selection bias. A conceptual model that organizes the known or postulated risk variables (neurological, psychosocial, and medication) is presented, with emphasis on psychology's potential contribution.     

Local and global orientation in visual search

Six experiments investigated the role of global (shape) and local (contour) orientation in visual search for an orientation target. Experiment 1 demonstrated thatsearch for a conjunction of local contours with a distinct global orientation was less efficient than search for a target featurally distinct in terms of both global and local contour orientation. However, Experiments 2 and 4 demonstrated that the presence of a unique line contour was neither sufficient nor necessary to allow efficient search. Experiment 5 found thatsearch for a local orientation difference was strongly impeded by irrelevant variation in global orientation, arguing for a preeminent role for global orientation. Finally, Experiment 6 demonstrated that the orientation search asymmetry holds for the global orientation of stimuli. Taken together, the results are consistent with visual search processes guided predominately by a representation of global orientation.     

Evaluating interobserver reliability of interval data

Previous recommendations to employ occurrence, nonoccurrence, and overall estimates of interobserver reliability for interval data are reviewed. A rationale for comparing obtained reliability to reliability that would result from a random-chance model is explained. Formulae and graphic functions are presented to allow for the determination of chance agreement for each of the three indices, given any obtained per cent of intervals in which a response is recorded to occur. All indices are interpretable throughout the range of possible obtained values for the per cent of intervals in which a response is recorded. The level of chance agreement simply changes with changing values. Statistical procedures that could be used to determine whether obtained reliability is significantly superior to chance reliability are reviewed. These procedures are rejected because they yield significance levels that are partly a function of sample sizes and because there are no general rules to govern acceptable significance levels depending on the sizes of samples employed.     

Effects of verbal imitation and comprehension training on verbal production

This study sought to determine whether some combination of imitation training and comprehension training was necessary to achieve verbal production or whether comprehension training alone was sufficient to result in verbal production. Fifty-one first- and second-grade subjects were trained to imitate eight words (Spanish nouns) for which there were no referents. An additional set of eight words was trained in a comprehension task where overt verbal rehearsal was prohibited. Once criterion of two successive sessions of 100% performance was reached in training for both imitation and comprehension, training modes were reversed so that items initially trained in imitation were then trained in comprehension andvice versa. Results showed that initial comprehension training did result in some verbal production, whereas initial imitation training, as expected, did not. A marked improvement in verbal production performance was observed when initial comprehension training was followed by imitation training. When initial imitation training was followed by comprehension training, verbal production also resulted but not to the degree or with the consistency of performance which marked the comprehension-then-imitation sequence. Furthermore, comprehension training required more trials to reach a similar level of proficiency when it followed imitation training than when it preceded imitation. These data indicate that initial imitation training interferes with acquisition of subsequent comprehension and production responses and that the preferred training sequence is one which initially focuses on comprehension and follows this with verbal imitation.This study was supported by Grant HD 00870 from the National Institute of Child Health and Human Development and Grant NS 10468 from the National Institute of Neurological Diseases and Stroke awarded to the Bureau of Child Research, University of Kansas, Lawrence, Kansas.