Algebras of Intervals and a Logic of Conditional Assertions

Intervals in boolean algebras enter into the study of conditional assertions (or events) in two ways: directly, either from intuitive arguments or from Goodman, Nguyen and Walker's representation theorem, as suitable mathematical entities to bear conditional probabilities, or indirectly, via a representation theorem for the family of algebras associated with de Finetti's three-valued logic of conditional assertions/events. Further representation theorems forge a connection with rough sets. The representation theorems and an equivalent of the boolean prime ideal theorem yield an algebraic completeness theorem for the three-valued logic. This in turn leads to a Henkin-style completeness theorem. Adequacy with respect to a family of Kripke models for de Finetti's logic, ukasiewicz's three-valued logic and Priest's Logic of Paradox is demonstrated. The extension to first-order yields a short proof of adequacy for Körner's logic of inexact predicates.     

Selective influence through conditional independence

Let each of several (generally interdependent) random vectors, taken separately, be influenced by a particular set of external factors. Under what kind of the joint dependence of these vectors on the union of these factor sets can one say that each vector is selectively influenced by “its own” factor set? The answer proposed and elaborated in this paper is: One can say this if and only if one can find a factor-independent random vector given whose value the vectors in question are conditionally independent, with their conditional distributions selectively influenced by the corresponding factor sets. Equivalently, the random vectors should be representable as deterministic functions of “their” factor sets and of some mutually independent and factor-independent random variables, some of which may be shared by several of the functions.     

Criterion-related construct validity

Established results on latent variable models are applied to the study of the validity of a psychological test. When the test predicts a criterion by measuring a unidimensional latent construct, not only must the total score predict the criterion, but the joint distribution of criterion scores and item responses must exhibit a certain pattern. The presence of this population pattern may be tested with sample data using the stratified Wilcoxon rank sum test. Often, criterion information is available only for selected examinees, for instance, those who are admitted or hired. Three cases are discussed: (i) selection at random, (ii) selection based on the current test, and (iii) selection based on other measures of the latent construct. Discriminant validity is also discussed.This work was supported in part by Grant SES-87-01890 from the Measurement Methods and Data Improvement Program of the U.S. National Science Foundation.     

四卡问题解决中的内容与逻辑分析效应

选取条件概率(P(Q|P))由低到高的四个命题作为四卡问题中的检验规则,探讨了大学生被试对四张卡片的逻辑证明作用的推断能力及其对解决四卡问题的影响。结果发现:(1)不同条件概率的命题之间正确选择P-Q的人数百分比不存在显著差异,命题的条件概率因素对四卡问题的正确解决没有影响。(2)逻辑分析过程对四卡问题的正确解决产生了一定的抑制作用,这可能是因为被试不能从整体上思考四张卡片在命题检验中的逻辑作用的缘故。(3)一些被试即使在逻辑分析过程中表现出知道-Q卡片的证伪作用,仍然倾向于选择卡片Q而非-Q,这一现象再次证实了人类思维的非形式逻辑的一面。     

Observing responses maintained by conditional discriminative stimuli.

In a conditional discrimination procedure, pigeons' observing responses were analyzed to examine whether two color stimuli (blue or red), conditionally related to whether each of two line stimuli (vertical or horizontal) accompanied reinforcement or nonreinforcement, functioned as conditioned reinforcers. If a variable-interval (VI) 10-s requirement was fulfilled, an observing response produced onset of a color stimulus. A little later, a line stimulus was presented independently of responding, added to the color stimulus to form a compound stimulus. If 55 s elapsed with a response not having occurred either through 55 s or after the variable-interval 10-s had timed out, one of the color-line compound stimuli was presented independently of responding. To control for sensory reinforcement effects and for earlier entrance to the later link, a simple discrimination procedure also was conducted in which reinforcement was not correlated with the color stimuli but with the line stimuli only. As in the conditional discrimination, the observing response also could produce earlier presentation of blue or red. The observing response occurred more frequently during the conditional discrimination than during the simple discrimination. The results were related to different theoretical accounts of conditioned reinforcement, particularly the information hypothesis.     

Children's ascriptions of property rights with changes of ownership

Ownership is not a “natural” property of objects, but is determined by human intentions. Facts about who owns what may be altered by appropriate decisions. However, young children often deny the efficacy of transfer decisions, asserting that original owners retain rights to their property. In Experiment 1, 4–5-year-old and 7–8-year-old children and adults were asked to resolve disputes between initial owners and various types of receivers (finders, borrowers, buyers). Experiment 2 involved disputes both before and after transfers of ownership. At all ages participants privileged owners over non-owners and accepted the effectiveness of property transfers. Overall, children's intuitions about property rights were similar to those of adults. Observed differences may reflect older participants’ willingness to segregate property rights from other considerations in assessing the acceptability of actions.     

A social identity approach to explaining children's aggressive intentions

This study explored the effects of group norms, intra-group position, and age on the direct and indirect aggressive intentions of 247 children (aged 5.50 to 11.83 years). Participants were assigned to a team, with team norms (aggression vs. helping) and the child's position within the team (prototypical vs. peripheral–prototypical vs. peripheral) manipulated. Results showed that children in the aggressive norm condition reported greater aggressive intentions than those in the helping norm condition, although, when age was considered, this effect remained evident for younger, but not older, children. Similarly, intra-group position influenced the aggressive intentions of younger children only. For these children, when group norms supported aggression, prototypical members and peripheral members who anticipated a future prototypical position reported greater aggressive intentions than peripheral members who were given no information about their future position. The implications of these findings for understanding childhood aggression, and for intervention, are discussed.     

The impact of information about the prevalence of AIDS-Preventive behavior among men and women: The mediating role of social norms

Abstract

The present study was designed to examine the effect of information about the high prevalence of safe sex on condom use intention, and to investigate the possible mediating role of the perceived social norm of friends, and the perceived social norm of future. sexual partners. Participants were provided with gender specific prevalence information, that is with the information that most men have exclusively safe sex, or with the information that most women exclusively engage in safe sexual behavior. The results show some gender differences. Information about the high prevalence of safe sex among men tends to increase women's condom use intention, and this effect seems to be mediated by the paceived social norm of future sexual partners. Men's intention, on the other hand, seems to be unaffected by high prevalence information of safe sex. Implications for research and prevention are discussed     

Predictable Mispredictions in the Context of Physical Activity and Sport: A Review

Theoretical models and research that aim to identify antecedents of participation in physical activities or sport can measure antecedents of physical activity behaviour through instruments that involve subjective predictions. In this article, we argue that such instruments may not reflect physical activity experiences or behaviour accurately because people are not very good predictors of future states. Additionally, we propose that mispredictions may be predictable because they are “caused” by tendencies to neglect processes related to hedonic adaptation and competing alternatives. We also suggest that it may be possible to improve measurement of antecedents through methods that focus respondents' attention on factors that cause mispredictions or through experiential sampling methods.     

Body image concern among Australian adolescent girls: The role of body comparisons with models and peers

This study investigated the potential mediating roles of body comparisons with peers and models in the relationship between the internalization of thinness norms and body image concern. A total of 224 Western Australian girls aged 14–15 completed questionnaires assessing their endorsement of thinness norms, body image concerns, and frequency of body comparisons with peers and with models. Both targets of body comparisons were found to significantly mediate the relationship between the endorsement of thinness norms and body image concern, with body comparison with peers a stronger mediator than comparison with models. These findings show that body comparison with peers, in particular, plays a significant role in the experience of body image concerns among adolescent girls, and should be given a higher profile in programs designed to prevent or reduce body image concern.