The semantics ofR4

The LogicR4 is obtained by adding the axiom (A vB(AvB) to the modal relevant logicNR. We produce a model theory for this logic and show completeness. We also show that there is a natural embedding of a Kripke model forS4 in eachR4 model structure.We are indebted to several people for discussions relating to the topic of this paper, in particular, Kit Fine, John Slaney, J. M. Dunn, Jacques Riche, M. A. McRobbie, and Jill LeBlanc. We would also like to thank the Automated Reasoning Project for material assistance. Mares would like to thank The Social Sciences and Humanities Research Council of Canada for fellowships 456-89-0128 and 457-90-0081, which supported him while writing this paper.     

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.     

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).     

Stressors, Stress Mediators, and Emotional Weil-Being Among Spouses of Soldiers Deployed to the Persian Gulf During Operation Desert Shield/Storm

The Family Factors Field Study of Operation Desert Shield/Storm (ODS) was designed to collect data on the impact of the Persian Gulf deployment on soldier/family well-being, and the effectiveness of Army and community resources in assisting and supporting families of deployed soldiers. In October 1990, a task force was assembled, and multi-agency research teams visited several Army installations. Informal individual and group interviews were conducted with spouses, unit family support leaders, unit rear detachment personnel, garrison leaders, and local Army program/service providers. The questions were aimed at identifying key stressors which spouses and children experienced in relation to the sudden deployment, as well a stress mediators such as social supports and personal coping skills. Anecdotal information collected during the site visits, combined with findings from previous research on Army families, was used to develop a questionnaire designed to quantify those variables which emerged as relevant to a study of stressors and stress mediators in the context of the ODS deployment.     

Unit price as a useful metric in analyzing effects of reinforcer magnitude.

In this paper, we applied the behavioral-economic concept of unit price to the study of reinforcer magnitude in an attempt to provide a consistent account of the effects of reinforcer magnitude on behavior. Recent research in the experimental analysis of behavior and in behavioral pharmacology suggests that reinforcer magnitude interacts with the schedule of reinforcement to determine response rate and total consumption. The utility of the unit-price concept thus stems from its ability to quantify this interaction as a cost-benefit ratio (i.e., unit price = characteristics of the schedule of reinforcement divided by magnitude of reinforcement). Research employing the unit-price concept has shown that as unit price increases, a positively decelerating function exists for consumption (i.e., a function with an increasingly negative slope, when plotted on log coordinates) and a bitonic function exists for response rate. Based on these findings, the present analysis applied the unit-price concept to those studies of reinforcer magnitude and drug self-administration that examined the effects of reinforcer magnitude on response rate using simple schedules of reinforcement (e.g., fixed-ratio schedule). This resulted in three findings: (a) Reinforcer-magnitude manipulations and schedule manipulations interact in a manner that can be quantified in terms of unit price as benefit and cost factors, respectively; (b) different reinforcer-magnitude manipulations are functionally interchangeable as benefit factors in the unit-price ratio; and (c) these conclusions appear warranted despite the differences in reinforcers (food or drug), species (dogs, monkeys, or rats), and schedules (interval or ratio), and despite the fact that these studies were not designed for a unit-price analysis. In methodological terms, these results provide further evidence that employing the unit-price concept is a parsimonious method for examining the effects of reinforcer magnitude. In theoretical terms, these results suggest that a single process may underlie the effect of combined reinforcer-magnitude and schedule manipulations.     

TEMPORAL CONTROL ON INTERVAL SCHEDULES: WHAT DETERMINES THE POSTREINFORCEMENT PAUSE?

On fixed-interval or response-initiated delay schedules of reinforcement, the average pause following food presentation is proportional to the interfood interval. Moreover, when a number of intervals of different durations occur in a programmed cyclic series, postreinforcement pauses track the changes in interval value. What controls the duration of postreinforcement pauses under these conditions? Staddon, Wynne, and Higa (1991), in their linear waiting model, propose control by the preceding interfood interval. Another possibility is that delay to reinforcement, signaled by a key peck and/or stimulus change, determines the subsequent pause. The experiments reported here examined the role of these two possible time markers by studying the performance of pigeons under a chained cyclic fixed-interval procedure. The data support the linear waiting model, but suggest that more than the immediately preceding interfood interval plays a role in temporal control.     

Schedule-induced defecation by rats during ratio and interval schedules of food reinforcement.

Lever pressing in rats was maintained by continuous and intermittent schedules of food while defecation was monitored. In Experiment 1, reinforcement densities were matched across variable-ratio and variable-interval schedules for three pairs of rats. Defecation occurred in all 3 rats on the variable-ratio schedule and in all 3 rats on the yoked variable-interval schedule. In Experiment 2, fixed-ratio and fixed-interval schedules with similar reinforcement densities maintained lever pressing. Defecation occurred in 3 of 4 rats on the fixed-ratio schedule and in 4 of 4 rats on the fixed-interval schedule. Almost no defecation occurred during continuous reinforcement in either experiment. These results demonstrate that defecation may occur during both ratio and interval schedules and that the inter-reinforcement interval is more important than the behavioral requirements of the schedule in generating schedule-induced defecation.     

Dynamic spatial performance and general intelligence

A computerized video-game-like dynamic spatial ability measure and a paper-and-pencil group test of intelligence were administered to 94 university students. The purpose of the study was threefold: (a) to evaluate the reliability of the dynamic spatial measure; (b) to investigate the extent to which the dynamic spatial measure is saturated with variance associated with traditional measures of fluid and crystallized intellectual ability; and (c) to explore the possibility that dynamic computer based performance measures define factors that are distinct from those associated with traditional paper-and-pencil measures. The number of times the participant hit a moving target served as the dependent variable for the dynamic spatial measure. Number of hits proved to be correlated with Performance IQ, but was not significantly correlated with Verbal IQ. Maximum likelihood factor analysis revealed that the dynamic spatial measure did not load substantially on a factor of general intellectual ability but provided additional evidence that it is related to a performance component.     

Why Religion Should Be an Integral Part of Public School Education

Studies of classroom climates completed in the 1980s concluded that religion, even broadly defined, is seldom discussed in public schools. This situation is inconsistent with important precedents of our society, and therefore, public schools ought rightly to provide opportunities for students to discuss religion, broadly defined, in a scholarly fashion throughout their normal school routine. This article delineates 10 logical and cultural underpinnings for religious instruction in public schools.