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1.
A model for signal detectability suggested by Luce is extended to situations in which the observer is uncertain of some important characteristic of the signal, such as frequency. By making a single assumption concerning the observer's covert response behavior, two solutions are obtained corresponding to qualitatively different behavior. Decrements in detectability and in recognition with uncertainty are shown to be particular functions of discriminability and detectability of the stimuli in other situations. Relevant experimental data are considered.This work was supported by grant NSF-G5544 from the National Science Foundation. The author is indebted to R. Duncan Luce for critical discussion of the content and helpful suggestions concerning the form of this paper. Useful comments have been made by David M. Green, Francis W. Irwin, Roger M. Shepard, and W. P. Tanner, Jr.  相似文献   

2.
Poor linkage cracks are defined and identified empirically in a postdisaster service delivery network. These cracks exist when essential services are provided only by isolated or peripheral clusters of organizations. Network analysis is used to identify the isolated and peripheral clusters of organizations. Measures of experience in responding to disasters and service capacity are used to identify the organizations whose services are essential in the network. Cracks prevent the network from responding effectively in the aftermath of a disaster. Suggestions are made for using network analysis to identify cracks and to improve planning and coordination in all kinds of service networks. Collection of the data for this work was supported by the National Science Foundation (NSF), Societal Response to Earthquake Hazards Mitigation Program, Grant No. CEE-8314421. The analysis and writing were accomplised with support from the National Science Foundation, Grant No. BCS-8920472. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the National Science Foundation. An early version of this paper was presented at the annual meetings of the Midwest Sociological Society, Des Moines, Iowa, April 1991. This paper was distinctly improved through our response to extensive and perceptive suggestions given by the editor and reviewers of theAmerican Journal of Community Psychology. We thank them for the help.  相似文献   

3.
Norman Cliff 《Psychometrika》1970,35(2):163-178
Data are reported which show the statistical relation between the sample and population characteristic vectors of correlation matrices with squared multiple correlations as communality estimates. Sampling fluctuations were found to relate only to differences in the square roots of characteristic roots and to sample size. A principle for determining the number of factors to rotate and interpret after rotation is suggested.This study was supported by the National Science Foundation, Grant GB 4230. The author wishes to express his appreciation for the use of Western Data Processing Center and the Health Sciences Computing Facility, UCLA. He also thanks Dr. Roger Pennell for extremely valuable assistance in a number of phases of the study.  相似文献   

4.
This paper examines tensions between two visions of schooling. One stresses social cohesion (i.e., common beliefs, shared activities, and caring relations between members). The other emphasizes strong academic mission (i.e., values and practices that reinforce high standards for student performance). Though not incongruous, numerous organizational studies reveal the potential for social cohesion and communality to be achieved at the expense of academic demand or “press.” To examine their separate and joint effects, measures of academic press and communality are developed from NELS:88 First Follow-up data. Results of hierarchical regression analyses indicate (1) significant links between academic press and student achievement; (2) that academic press has its greatest achievement effect among low-SES schools; (3) that strong sense of community may have a negative impact on achievement in low-SES schools with weak academic press; and (4) that for low- and middle-SES schools, the greatest achievement effects follow from strong combinations of communality and academic press. These findings highlight an important additional component of the “school as community” model, indicating that for most schools, academic press serves as a key prerequisite for the positive achievement effects of communality. The author wishes to express appreciation to National Science Foundation for it support under the grant “Improving Mathematics and Science Learning: A School and Classroom Approach” (RED-9255880). The views expressed here are those of the author, and no official endorsement by the National Science Foundation is intended or should be inferred. Correspondence concerning this article should be sent to Roger C. Shouse, The Pennsylvania State University, 315 Rackley Building, University Park, PA 16803, U.S.A.  相似文献   

5.
A formal theory of appropriateness for statistical operations is presented which incorporates features of Stevens' theory of appropriate statistics and Suppes' theory of empirical meaningfulness. It is proposed that a statistic be regarded as appropriate relative to statements made about it in case the truths of these statements are invariant under permissible transformations of the measurement scale. It is argued that the use of inappropriate statistics leads to the formulation of statements which are either semantically meaning-less or empirically nonsignificant.This research was supported in part by each of the following grants: National Science Foundation Grant GS-333 to the University of Oregon; National Science Foundation Grant to the Institute of Human Learning, University of California, Berkeley; and National Institute of Mental Health Grant MH-08055-01 (under the direction of Ernest W. Adams), also to the Institute of Human Learning. Work on this project was carried out in part during Robert F. Fagot's tenure as Public Health Service Special Fellow (No. MSP-15800) at the University of California, Berkeley, 1962-63; and during Richard E. Robinson's tenure as National Science Foundation Science Faculty Fellow at Stanford University, 1962–63.  相似文献   

6.
J. O. Ramsay 《Psychometrika》1969,34(2):167-182
Some shortcomings of current methods of estimating the magnitude of perceived difference are considered. A statistical model for perceived difference is derived which avoids these difficulties and employs judgments of ratios of differences as data. Three estimators of squared difference are developed.This study was conducted while the author was a Psychometric Fellow at Princeton University and Educational Testing Service and is part of a dissertation presented in candidacy for the degree of doctor of philosophy. This research was supported by Office of Naval Research Contract Nonr 1858 and by National Science Foundation Grant GB3402. Extensive use was made of the computing facilities of Princeton University supported in part by National Science Foundation Grant NSF-GP579. The author wishes to express his appreciation to Prof. H. Gulliksen, Prof. F. Geldard, Dr. C. Helm, and Dr. F. Lord for their comments and encouragement.  相似文献   

7.
Mapclus: A mathematical programming approach to fitting the adclus model   总被引:6,自引:0,他引:6  
We present a new algorithm, MAPCLUS (MAthematicalProgrammingCLUStering), for fitting the Shepard-Arabie ADCLUS (forADditiveCLUStering) model. MAPCLUS utilizes an alternating least squares method combined with a mathematical programming optimization procedure based on a penalty function approach, to impose discrete (0,1) constraints on parameters defining cluster membership. This procedure is supplemented by several other numerical techniques (notably a heuristically based combinatorial optimization procedure) to provide an efficient general-purpose computer implemented algorithm for obtaining ADCLUS representations. MAPCLUS is illustrated with an application to one of the examples given by Shepard and Arabie using the older ADCLUS procedure. The MAPCLUS solution uses half as many clusters to achieve nearly the same level of goodness-of-fit. Finally, we consider an extension of the present approach to fitting a three-way generalization of the ADCLUS model, called INDCLUS (INdividualDifferencesCLUStering).We are indebted to Scott A. Boorman, W. K. Estes, J. A. Hartigan, Lawrence J. Hubert, Carol L. Krumhansl, Joseph B. Kruskal, Sandra Pruzansky, Roger N. Shepard, Edward J. Shoben, Sigfrid D. Soli, and Amos Tversky for helpful discussions of this work, as well as the anonymous referees for their suggestions and corrections on an earlier version of this paper. We are also grateful to Pamela Baker and Dan C. Knutson for technical assistance. The research reported here was supported in part by LEAA Grant 78-NI-AX-0142 and NSF Grants SOC76-24512 and SOC76-24394.  相似文献   

8.
This paper generalizes thep* model for dichotomous social network data (Wasserman & Pattison, 1996) to the polytomous case. The generalization is achieved by transforming valued social networks into three-way binary arrays. This data transformation requires a modification of the Hammersley-Clifford theorem that underpins thep* class of models. We demonstrate that, provided that certain (non-observed) data patterns are excluded from consideration, a suitable version of the theorem can be developed. We also show that the approach amounts to a model for multiple logits derived from a pseudo-likelihood function. Estimation within this model is analogous to the separate fitting of multinomial baseline logits, except that the Hammersley-Clifford theorem requires the equating of certain parameters across logits. The paper describes how to convert a valued network into a data array suitable for fitting the model and provides some illustrative empirical examples.This research was supported by grants from the Australian Research Council, the National Science Foundation (#SBR96-30754), and the National Institute of Health (#PHS-1RO1-39829-01).  相似文献   

9.
Whereas previous studies have criticized low-quality products for inadequate safety, this paper considers only safe products, and it examines the ethics of designing and selling low-quality products. Product quality is defined as suitability to a general purpose. The duty that companies owe to consumers is summarized in the Consumer-Oriented Process principle: “to place an increase in the consumer’s quality of life as the primary goal for producing products.” This principle is applied in analyzing the primary ethical justifications for low-quality products: availability and applicability. Finally, a low-quality product should be designed afresh, not by altering an existing high-quality product. Supported by the National Science Foundation under Grant CCR-9315696. The views, opinions, and conclusions of this paper are not necessarily those of the University of Illinois or the National Science Foundation. A preliminary version of this paper was presented at the Fifth Annual Meeting of the Association for Practical and Professional Ethics, St. Louis, Mo., February 29 to March 2, 1996. Willem Bakker is an undergraduate at the University of Illinois at Urbana-Champaign. He is majoring in computer engineering and philosophy. Michael Loui is professor of electrical and computer engineering and associate dean of the Graduate College at the University of Illinois at Urbana-Champaign. From 1990 to 1991, he served at the National Science Foundation in Washington, D.C. His scholarly interests include computational complexity theory, theory of parallel and distributed computation, faulttolerant software, and professional ethics.  相似文献   

10.
A random effects probit model is developed for the case in which the same units are sampled repeatedly at each level of an independent variable. Because the observed proportions may be correlated under these conditions, estimating their trend with respect to the independent variable is no longer a standard problem for probit, logit or loglinear analysis. Using a qualitative analogue of a random regressions model, we employ instead marginal maximum likelihood to estimate the average latent trend line. Likelihood ratio tests of the hypothesis of no trend in the average line, and the hypothesis of no differences in average trend lines between experimental treatments, are proposed. We illustrate the model both with simulated data and with observed data from a clinical experiment in which psychiatric patients on two drug therapies are rated on five occasions for the presence or absence of symptoms.Supported by a grant from the MacArthur Foundation and National Science Foundation Grant BNS85-11774.The authors are indebted to James Heckman for calling our attention to the Clark algorithm.  相似文献   

11.
Kaiser's measure of sampling adequacy is applied to a special Spearman matrix and a specialq-cluster generalization. The result supports the contention that the measure should be no less than .5 for data to be appropriate for factor analysis.The research reported in this note was supported in part by the Program in Applied Mathematics and Statistics, National Science Foundation, and by the National Institute of Education, Department of Health, Education, and Welfare.  相似文献   

12.
A review of the literature on children's use of relative clause constructions reveals many contradictory findings. The suggestion is that some studies fail to take into account the two factors of embeddedness (role of complex noun phrase within the sentence) and focus (role of head noun in the relative clause). The experiment reported here attempted to reconcile the disparate findings and extend the range of constructions examined. 114 children between the ages of 3 and 7 served as subjects in a test of comprehension using an act-out procedure of 9 different relative clause sentences that exhaust the possible combination of 3 roles of the complex noun phrase in the sentence and 3 roles that the head noun plays within the relative clause (in each case, subject, driect object, and indirect object). All constructions were understood better with increasing age of the children sex and sentence set were nonsignificant variables. The results reveal a difficulty in ordering of the 9 types of construction that is in keeping with a prediction based on surface structure processing strategies.This research was supported by grant No. BNS73-09150 from the National Science Foundation to Professor Roger Brown.  相似文献   

13.
The research reported herein was supported by funds from The National Science Foundation. The opinions expressed do not necessarily reflect the position or policy of the National Science Foundation and no official endorsement should be inferred.  相似文献   

14.
Omitted items cannot properly be treated as wrong when estimating ability and item parameters. A convenient method for utilizing the information provided by omissions is presented. Theoretical and empirical justifications are presented for the estimates obtained by the new method.Research reported in this paper has been supported by grant GB-32781X from National Science Foundation.  相似文献   

15.
Nonmetric multidimensional scaling: Recovery of metric information   总被引:1,自引:0,他引:1  
The degree of metric determinancy afforded by nonmetric multidimensional scaling was investigated as a function of the number of points being scaled, the true dimensionality of the data being scaled, and the amount of error contained in the data being scaled. It was found 1) that if the ratio of the degrees of freedom of the data to that of the coordinates is sufficiently large then metric information is recovered even when random error is present; and 2) when the number of points being scaled increases the stress of the solution increases even though the degree of metric determinacy increases.This report was supported in part by a PHS research grant No. M-10006 from the National Institute of Mental Health, Public Health Service, and in part by a Science Development grant No. GU-2059, from the National Science Foundation. The author is indebted to Charles R. Sherman for his assistance in gathering the data and for his critical re-writing of sections of this report. The assistance of Lyle V. Jones in his critical readings and comments is also deeply appreciated.  相似文献   

16.
Cheiron, the International Society for the History of Behavioral and Social Sciences, was established in 1968 as an outcome of a National Science Foundation summer institute directed by Robert Watson and Josef Brožek. In subsequent years the society has developed into an effective organization for stimulating and disseminating scholarly work, through sponsoring an annual meeting and encouraging a communication network. This article notes Watson's support of Cheiron as one of his contributions to establishing the history of psychology as a specialty field.  相似文献   

17.
A general latent variable model is given which includes the specification of a missing data mechanism. This framework allows for an elucidating discussion of existing general multivariate theory bearing on maximum likelihood estimation with missing data. Here, missing completely at random is not a prerequisite for unbiased estimation in large samples, as when using the traditional listwise or pairwise present data approaches. The theory is connected with old and new results in the area of selection and factorial invariance. It is pointed out that in many applications, maximum likelihood estimation with missing data may be carried out by existing structural equation modeling software, such as LISREL and LISCOMP. Several sets of artifical data are generated within the general model framework. The proposed estimator is compared to the two traditional ones and found superior.The research of the first author was supported by grant No. SES-8312583 from the National Science Foundation and by a Spencer Foundation grant. We wish to thank Chuen-Rong Chan for drawing the path diagram.  相似文献   

18.
Commonality components have been defined as a method of partitioning squared multiple correlations. In this paper, the asymptotic joint distribution of all 2 k – 1 squared multiple correlations is derived. The asymptotic joint distribution of linear combinations of squared multiple correlations is obtained as a corollary. In particular, the asymptotic joint distribution of commonality components are derived as a special case. Simultaneous and nonsimultaneous asymptotic confidence intervals for commonality components can be obtained from this distribution.This work was supported in part by the Spencer Foundation and the National Science Foundation.The authors are grateful to Bryna Siegel-Gorlick for her help in obtaining the data used in Example 4.3, and to the referees for their comments and suggestions.  相似文献   

19.
Unlike their monotone counterparts, nonparametric unfolding response models, which assume the item response function is unimodal, have seen little attention in the psychometric literature. This paper studies the nonparametric behavior of unfolding models by building on the work of Post (1992). The paper provides rigorous justification for a class of nonparametric estimators of respondents’ latent attitudes by proving that the estimators consistently rank order the respondents. The paper also suggests an algorithm for the rank ordering of items along the attitudes scale. Finally, the methods are evaluated using simulated data. This research was supported in part by an Educational Testing Service Gulliksen Fellowship, and by the National Science Foundation, Grant DMS-97.05032. The author would like to thank Brian Junker for his help and support on this paper and Paul Holland, Steve Fienberg, and Jay Kadane for their helpful comments.  相似文献   

20.
A language for quantum physics is derived from set theory by replacing the classical predicate algebra (Boolean) by a certain quantum predicate algebra (rational projective), time space and the Hamilton-Schroedinger dynamics by a Feynman-like graph dynamics, and the Dirac spin operators by topological switching operators on the graph. The development is described from the basic level of elementary monadic processes to the level of the free Dirac equation. Young Men's Philanthropic League Professor of Physics. Supported by the est Foundation and the National Science Foundation.  相似文献   

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