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71.
A theory of justice for the basic structure of society may constrain though not directly govern colleges. The principle of "equal opportunity" commonly applied to jobs either does or does not apply to varsity opportunities. If it applies, it interdicts sex discrimination but, one fallacious argument notwithstanding, it states no obligation to expend resources on new teams. If it does not apply, an analogue of Rawls's difference principle may appropriately constrain inequalities between the sexes. In either case the preferences of a majority of the sex affected by any inequality are pivotal in fashioning any tenable distributive policy. Those preferences are neglected by a government policy that assimilates equal opportunity to equality of (i) the ratio of male:female varsity athletes and (ii) the ratio of male:female students. It is argued that such policy rests on affirming the consequent. Its effects include misallocations of resources and overvaluation of athletics. It is argued that what should approximately be equal is competitive access, the ratio of available positions to aspirants, for each sex. Two versions of a principle of equal competitive access are proposed, the recommended one of which pertains to teams whose net consumption of resources is positive. 相似文献
72.
The possibility of obtaining locally optimal solutions with categorical data is pointed out for the original version of OSMOD development by Saito and Otsu. A revision of the initialization strategy in OSMOD is suggested, and its effectiveness in diminishing this possibility is demonstrated. 相似文献
73.
Simple procedures are described for obtaining maximum likelihood estimates of the location and uncertainty parameters of the
Hefner model. This model is a probabilistic, multidimensional scaling model, which assigns a multivariate normal distribution
to each stimulus point. It is shown that for such a model, standard nonmetric and metric algorithms are not appropriate.
A procedure is also described for constructing incomplete data sets, by taking into consideration the degree of familiarity
the subject has for each stimulus. Maximum likelihood estimates are developed both for complete and incomplete data sets.
This research was supported by National Science Grant No. SOC76-20517. The first author would especially like to express his
gratitude to the Netherlands Institute for Advanced Study for its very substantial help with this research. 相似文献
74.
Andrew K. Clark 《Psychometrika》1976,41(3):401-403
Critical examination is made of the recent controversy over the value of Monte Carlo techniques in nonmetric multidimensional scaling procedures. The case is presented that the major relevance of Monte Carlo studies is not for the local minima problem but for the meaningfulness of the obtained solutions. 相似文献
75.
In the continuous response (CR) task, the subject is given the name of a familiar category and must respond with category examples within a fixed time limit. The response sequence and the interresponse times are the measured variables. A general model is proposed for performance in the CR task. The time taken to generate a response is identified with the shortest search time from among a set of simultaneous search processes. Each response has a generation probability that is a function of the parameters governing the search process durations. Data involving the category states in the United States are used to test the model. The model accounts for the performance of nearly all individuals in these data.This article is based on a dissertation completed at the University of California-Berkeley in partial fullfillment of the requirements for the Ph.D. degree in psychology. Portions of the article were presented at the joint meeting of the Psychometric and Classification Societies (June 1984) and at the meeting of the Society for Mathematical Psychology (August 1984). The authors wish to thank Barbara Mellers, Juliet Schaffer, Steve Palmer, and Eleanor Rosch for helpful comments. 相似文献
76.
On the distinction between open and closed economies. 总被引:4,自引:3,他引:1
Open and closed economies have been assumed to produce opposite relations between responding and the programmed density of reward (the amount of reward divided by its cost). Experimental procedures that are treated as open economies typically dissociate responding and total reward by providing supplemental income outside the experimental session; procedures construed as closed economies do not. In an open economy responding is assumed to be directly related to reward density, whereas in a closed economy responding is assumed to be inversely related to reward density. In contrast to this predicted correlation between response-reward relations and type of economy, behavior regulation theory predicts both direct and inverse relations in both open and closed economies. Specifically, responding should be a bitonic function of reward density regardless of the type of economy and is dependent only on the ratio of the schedule terms rather than on their absolute size. These predictions were tested by four experiments in which pigeons' key pecking produced food on fixed-ratio and variable-interval schedules over a range of reward magnitudes and under several open- and closed-economy procedures. The results better supported the behavior regulation view by showing a general bitonic function between key pecking and food density in all conditions. In most cases, the absolute size of the schedule requirement and the magnitude of reward had no effect; equal ratios of these terms produced approximately equal responding. 相似文献
77.
D A Stubbs 《Journal of the experimental analysis of behavior》1980,33(2):167-185
Pigeons were presented a series of keylight time periods (separated by blackouts) during which two response keys were lit, one by blue light and the other either by orange or green. Blue-key responses changed the color on the other key. Orange-key responses sometimes produced food during the first half of a time period; green-key responses sometimes produced food during the second half. In three experiments, the probability of a green-key response increased as a function of elapsed time. Experiment 1 compared performance when the duration of the keylight periods was varied across a wide range. Discrimination of performance was similar across the range of durations. Experiment 2 varied both relative reinforcement rate and the local reinforcement rate for orange-key and green-key responses. These manipulations produced changes in response bias but not discrimination sensitivity. Experiment 3 varied the local temporal placement of reinforcers within time periods and demonstrated that choice behavior was affected by differential reinforcement at different points during the time periods. The results were consistent with previous research on duration discrimination that used psychophysical trials procedures. 相似文献
78.
A procedure for computing the power of the likelihood ratio test used in the context of covariance structure analysis is derived. The procedure uses statistics associated with the standard output of the computer programs commonly used and assumes that a specific alternative value of the parameter vector is specified. Using the noncentral Chi-square distribution, the power of the test is approximated by the asymptotic one for a sequence of local alternatives. The procedure is illustrated by an example. A Monte Carlo experiment also shows how good the approximation is for a specific case.This research was made possible by a grant from the Dutch Organization for Advancement of Pure Research (ZWO). The authors also like to acknowledge the helpful comments and suggestions from the editor and anonymous reviewers. 相似文献
79.
80.
A functional near-infrared spectroscopy study of sustained attention to local and global target features 总被引:1,自引:0,他引:1
Despite a long history of vigilance research, the role of global and local feature discrimination in vigilance tasks has been relatively neglected. In this experiment participants performed a sustained attention task requiring either global or local shape stimuli discrimination. Reaction time to local feature discriminations was characterized by a quadratic trend over time-on-task with performance levels returning to initial levels late in the task. This trend did not occur in the global shape discrimination task. Functional near-infrared spectroscopy (fNIRS) was utilized in this study as an index of cerebral activation. In both tasks there was increased right hemisphere relative to left hemisphere oxygenation and right hemisphere oxygenation increased with time-on-task. Left hemisphere oxygenation, however, decreased slightly in the global task, but increased significantly in the local task as task duration increased. Indeed, total oxygenation, averaging both right and left, increased more with time-on-task in the local discrimination task. Both the performance and physiological results of this study indicate increased utilization of bilateral cerebral resources with time-on-task in the local, but not the global discrimination vigil. 相似文献