Accuracy and precision of the PEAK Performance Technologies Motion Measurement System

This study evaluated the accuracy and precision of the PEAK Performance Technologies, lnc.'s motion analysis system for three-dimensional angle reconstruction. Pendular motion of a bar, on which 18 retroreflective markers were mounted, was videotaped at three different orientations (parallel, and rotated 30 degrees right and left) to a plane at which two standard video cameras were aimed. The videotaped motion was digitized off-line, and 32 angles between the 18 markers were calculated. intraclass correlation coefficients (ICCs) were calculated between trials within each pendulum orientation and across orientations to determine system precision, and between randomly selected trials and actual angles to determine accuracy. lCCs were in all cases greater than.99. Within-trial standard deviations ranged between 0.05-0.8 degrees for the different angles. Deviations from the actual angle averaged 0.0-0.8 degrees across all angles and orientations. The results indicate that accurate and reliable angular measurements can be made with this motion analysis system.     

A logic of intentions and beliefs

Intentions are an important concept in Artificial Intelligence and Cognitive Science. We present a formal theory of intentions and beliefs based on Discourse Representation Theory that captures many of their important logical properties. Unlike possible worlds approaches, this theory does not assume that agents are perfect reasoners, and gives a realistic view of their internal architecture; unlike most representational approaches, it has anobjective semantics, and does not rely on anad hoc labeling of the internal states of agents. We describe a minimal logic for intentions and beliefs that is sound and complete relative to our semantics. We discuss several additional axioms, and the constraints on the models that validate them.     

Relevant consequence and empirical inquiry

A criterion of adequacy is proposed for theories of relevant consequence. According to the criterion, scientists whose deductive reasoning is limited to some proposed subset of the standard consequence relation must not thereby suffer a reduction in scientific competence. A simple theory of relevant consequence is introduced and shown to satisfy the criterion with respect to a formally defined paradigm of empirical inquiry.Research support was provided by the Office of Naval Research under contract No. N00014-89-J-1725 to Osherson and Weinstein, Swiss National Science Foundation under contract No. 21-32399.91 and by a Siemens Corporation grant to Osherson.     

The imp of the reverse: A phenomenology of the unconscious

The debate regarding the unitary versus multiple nature of the human person is examined with special attention to the division between conscious and unconscious. The roots of the unconscious are traced to the experience of alienation or feeling divided within. An existential analysis is provided in order to shed light on the nature of the unconscious. The experience of feeling divided within is explained as a metaphor that is taken literally. An existential-phenomenological explanation of the unconscious is provided which preserves the essential unity of the human person.     

Twenty-five basic theorems in situation and world theory

Conclusion The foregoing set of theorems forms an effective foundation for the theory of situations and worlds. All twenty-five theorems seem to be basic, reasonable principles that structure the domains of properties, relations, states of affairs, situations, and worlds in true and philosophically interesting ways. They resolve 15 of the 19 choice points defined in Barwise (1989) (see Notes 22, 27, 31, 32, 35, 36, 39, 43, and 45). Moreover, important axioms and principles stipulated by situation theorists are derived (see Notes 33, 37, and 38). This is convincing evidence that the foregoing constitutes a theory of situations. Note that worlds are just a special kind of situation, and that the basic theorems of world theory, which were derived in previous work, can still be derived in this situation-theoretic setting. So there seems to be no fundamental incompatibility between situations and worlds — they may peacably coexist in the foundations of metaphysics. The theory may therefore reconcile two research programs that appeared to be heading off in different directions. And we must remind the reader that the general metaphysical principles underlying our theory were not designed with the application to situation theory in mind. This suggests that the general theory and the underlying distinction have explanatory power, for they seem to relate and systematize apparently unrelated phenomena.This research was conducted at the Center for the Study of Language and Information (CSLI). I would like to thank John Perry for generously supporting my research both at CSLI and in the Philosophy Department at Stanford. I would also like to thank Bernard Linsky, Chris Menzel, Harry Deutsch and Tony Anderson for many worthwhile and interesting suggestions for improving the paper. An earlier version of the paper, more narrowly focused on situation theory, has appeared in Zalta (1991).     

A Review of MMPI and Rorschach interrelationships in adult samples

The MMPI and Rorschach are consistently ranked among the most widely used psychological assessment instruments across adolescent and adult clinical settings. Although there is an extensive research literature available on each instrument individually, relatively little research attention has been focused on the interrelationships between these measures. This article reviews the literature derived from 37 studies that have reported interrelationships between MMPI and Rorschach variables in adult populations. The results of these studies generally indicate limited or minimal relationships between the MMPI and Rorschach. A number of methodological issues, however, prevent drawing firm conclusions from the literature at this time. Directions for future research are discussed, including consideration of issues related to sources of alpha and beta error and the need for studies examining the incremental validity of combinations of Rorschach and MMPI data in prediction to relevant external criteria.     

On the comparison of TAT and free speech techniques in personality assessment

Schnurr, Rosenberg, and Oxman (1992) recently compared the free speech samples and Thematic Apperception Test (TAT) responses of 95 normal adults. They concluded that the two techniques are not interchangeable, and that the TAT, which proved superior in the prediction of individual differences, may be preferable to free speech instructions for eliciting data in content analytic studies. We disagree with both conclusions. Various forms of narrative speech samples may be highly correlated, so long as psychologically meaningful, well-validated, and higher order content categories are used. The use of first-order content categories is less likely to contribute to the study of personality.     

Sexual Attitudes of Males and Females as Predictors of Interpersonal Attraction and Marital Compatibility1

Two investigations examine the effect of similarity of sexual attitudes on (a) attraction to a stranger and (b) marital sexual satisfaction. In an experiment using undergraduates, manipulation of subject-stranger similarity in general affective orientation to sexuality affected attraction and other evaluative dependent variables. In the second investigation, married couples revealed sexual attitudes and sexual satisfaction. Husbands and wives were similar (r= 0.58, p < 0.001) in their affective orientations to sexuality. Discrepancy between the partners’ scores predicted sexual dissatisfaction in both partners. In addition, the wife's affective orientation to sexuality predicted more indices of sexual satisfaction and adjustment in both the wife and the husband than did the husband's affective orientation to sexuality. Finally, spouses with a positive affective orientation to sexuality were more accurate when judging their partner's sexual enjoyment, compared to spouses with a negative orientation. The findings have implications for the effects of similarity of attitudes on interpersonal attraction and on relationship quality.     

Perceived Health Barriers and Health Value in Seniors: Implications for Well-Being and Mortality1

There is growing evidence to suggest that the ways in which people think about their health problems may have significant implications for psychological and physical well-being. This possibility has the greatest consequences for those groups facing health problems on a daily basis, in particular, the elderly. This study examined the role of perceived health barriers and value for health in later life. A Perceived Health Barriers (absent, present) by Health Value (low, medium, high) 2.3 factorial design was analyzed for younger and older seniors on: number of life-threatening diseases, need for health care, and life satisfaction. In addition, a longitudinal design was used to examine the joint roles of perceived health barriers (PHBs) and health value (HV) on mortality. Findings generally indicated that individuals’ PHBs and HV are associated with health-related outcomes; however, the results differed for young and old elders. Among young elders, those with PHBs and those with high HV had the most negati e profile. That is, they had more diseases, higher health care needs, and lower life satisfaction. Among older elders, the findings were more complicated in that the relationship between PHB and the outcomes depended on HV. Overall, the patterns for old elders suggest that perceived health barriers are most relevant among those with medium value for health and least relevant among those with low value for health.