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31.
On Similarity Coefficients for 2×2 Tables and Correction for Chance   总被引:2,自引:0,他引:2  
This paper studies correction for chance in coefficients that are linear functions of the observed proportion of agreement. The paper unifies and extends various results on correction for chance in the literature. A specific class of coefficients is used to illustrate the results derived in this paper. Coefficients in this class, e.g. the simple matching coefficient and the Dice/Sørenson coefficient, become equivalent after correction for chance, irrespective of what expectation is used. The coefficients become either Cohen’s kappa, Scott’s pi, Mak’s rho, Goodman and Kruskal’s lambda, or Hamann’s eta, depending on what expectation is considered appropriate. Both a multicategorical generalization and a multivariate generalization are discussed.  相似文献   
32.
Environments That Make Us Smart: Ecological Rationality   总被引:2,自引:0,他引:2  
ABSTRACT— Traditional views of rationality posit general-purpose decision mechanisms based on logic or optimization. The study of ecological rationality focuses on uncovering the "adaptive toolbox" of domain-specific simple heuristics that real, computationally bounded minds employ, and explaining how these heuristics produce accurate decisions by exploiting the structures of information in the environments in which they are applied. Knowing when and how people use particular heuristics can facilitate the shaping of environments to engender better decisions.  相似文献   
33.
In this paper, we show the weak normalization (WN) of the simply-typedse-calculus with open terms where abstractions are decoratedwith types, and metavariables, de Bruijn indices and updatingoperators are decorated with environments. We show a proof ofWN using the e-calculus, a calculus isomorphic to . This proof is strongly influenced by Goubault-Larrecq'sproof of WN for the -calculus but with subtle differences whichshow that the two styles require different attention. Furthermore,we give a new calculus 'e which works like se but which iscloser to than e. For both e and 'e we prove WN for typedsemi-open terms (i.e. those which allow term variables but nosubstitution variables), unlike the result of Goubault-Larrecqwhich covered all open terms.  相似文献   
34.
单纯性肾囊肿是临床常见的肾脏疾病之一,临床常采用去顶减压术治疗,但外科治疗的适应证目前尚不统一。除症状性肾囊肿及由囊肿引起尿路梗阻外,对于高血压病合并肾囊肿者,如囊肿直径大于5cm,考虑囊肿有可能对高血压产生影响,因此,有必要采取外科治疗措施;但如果不合并高血压,是否一定需要治疗有待进一步探讨。肾囊肿对肾功能影响目前尚无定论,对于小于60岁的肾囊肿患者其肾功能下降可能与肾脏原发病变有关,应积极查找病因并密切随访。对于肾囊肿Bosniak分型为Ⅰ、Ⅱ、ⅡF型的患者,可以不需要手术治疗,密切随访;对于Ⅲ、Ⅳ型患者,应进行外科手术治疗。  相似文献   
35.
36.
Monotonically convergent algorithms are described for maximizing six (constrained) functions of vectors x, or matricesX with columns x1, ..., x r . These functions are h1(x)= k (xA kx)(xC kx)–1, H1(X)= k tr (XA k X)(XC k X)–1, h1(X)= k l (x l A kx l ) (x l C kx l )–1 withX constrained to be columnwise orthonormal, h2(x)= k (xA kx)2(xC kx)–1 subject to xx=1, H2(X)= k tr(XA kX)(XAkX)(XCkX)–1 subject toXX=I, and h2(X)= k l (x l A kx l )2 (x l C kX l )–1 subject toXX=I. In these functions the matricesC k are assumed to be positive definite. The matricesA k can be arbitrary square matrices. The general formulation of the functions and the algorithms allows for application of the algorithms in various problems that arise in multivariate analysis. Several applications of the general algorithms are given. Specifically, algorithms are given for reciprocal principal components analysis, binormamin rotation, generalized discriminant analysis, variants of generalized principal components analysis, simple structure rotation for one of the latter variants, and set component analysis. For most of these methods the algorithms appear to be new, for the others the existing algorithms turn out to be special cases of the newly derived general algorithms.This research has been made possible by a fellowship from the Royal Netherlands Academy of Arts and Sciences to the author. The author is obliged to Jos ten Berge for stimulating this research and for helpful comments on an earlier version of this paper.  相似文献   
37.
Factor analysis and principal components analysis (PCA) are often followed by an orthomax rotation to rotate a loading matrix to simple structure. The simple structure is usually defined in terms of the simplicity of the columns of the loading matrix. In Three-mode PCA, rotational freedom of the so called core (a three-way array relating components for the three different modes) can be used similarly to find a simple structure of the core. Simple structure of the core can be defined with respect to all three modes simultaneously, possibly with different emphases on the different modes. The present paper provides a fully flexible approach for orthomax rotation of the core to simple structure with respect to three modes simultaneously. Computationally, this approach relies on repeated (two-way) orthomax applied to supermatrices containing the frontal, lateral or horizontal slabs, respectively. The procedure is illustrated by means of a number of exemplary analyses. As a by-product, application of the Three-mode Orthomax procedures to two-way arrays is shown to reveal interesting relations with and interpretations of existing two-way simple structure rotation techniques.This research has been made possible by a fellowship from the Royal Netherlands Academy of Arts and Sciences to the author. The author is obliged to Jos ten Berge and two anonymous reviewers for useful comments on an earlier version of this paper.  相似文献   
38.
A maximum likelihood estimation procedure was developed to fit unweighted and weighted additive models to conjoint data obtained by the categorical rating, the pair comparison or the directional ranking method. The scoring algorithm used to fit the models was found to be both reliable and efficient, and the program MAXADD is capable of handling up to 300 parameters to be estimated. Practical uses of the procedure are reported to demonstrate various advantages of the procedure as a statistical method.The research reported here was supported by Grant A6394 to the author from the Natural Sciences and Engineering Research Council of Canada. Portions of this research were presented at the Psychometric Society meeting in Iowa City, Iowa, in May, 1980.Thanks are due to Jim Ramsay, Justine Sergent and anonymous reviewers for their helpful comments.Two MAXADD programs which perform the computations discussed in this paper may be obtained from the author.  相似文献   
39.
Reanalysis of the equation for simple action   总被引:4,自引:4,他引:0       下载免费PDF全文
De Villiers and Herrnstein (1976) have shown that the equation for simple action, derived from the matching law, predicts change in behavioral output for some 40 experiments in which the value of a single source of reinforcement has been varied. Using only the positive-reinforcement studies they cite that used five or more different reinforcement values, we found the high percentage of variance they report accommodated by this equation (94%) is predicated on instances of averaging rates of behavioral output before making a least-squares fit of the equation. In our reanalysis, which minimizes rate averaging, only 78% of the data variance is accommodated. This diminished data-variance accommodation can be improved by adding parameters that permit the equation's scaling constant to change as a function of reinforcement. Although these parameters permit acceptable levels of accommodation of data variance, they correspond to no obvious psychological processes. These findings support the view that the equation for simple action is an inadequate model for behavioral output.  相似文献   
40.
Five pigeons were trained under concurrent-chain schedules in which a pair of independent, concurrent variable-interval 60-s schedules were presented in the initial link and either both variable-interval or both fixed-interval schedules were presented in the terminal link. Except for the baseline, one of the terminal-link schedules was always a two-component chained schedule and the other was either a simple or a tandem schedule of equal mean interreinforcement interval. The values of the fixed-interval schedules were either 15 s or 60 s; that of the variable-interval schedules was always 60 s. A 1.5-s changeover delay operated during the initial link in some conditions. The pigeons preferred a simple or a tandem schedule to a chain. For the fixed-interval schedules, this preference was greater when the fixed interval was 60 s than when it was 15 s. For the variable-interval schedules, the preferences were less pronounced and occurred only when the changeover delay was in effect. For a given type of schedule and interreinforcement interval, similar preferences were obtained whether the nonchained schedule was a tandem or simple schedule. The changeover delay generally inflated preference and lowered the changeover rate, especially when the terminal-link schedules were either short (15 s) or aperiodic (variable-interval). The results were consistent with the notion that segmenting the interreinforcement interval of a schedule into a chain lowers the preference for it.  相似文献   
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