Changes in functional response units with briefly delayed reinforcement

In two experiments, key-peck responding of pigeons was compared under variable-interval schedules that arranged immediate reinforcement and ones that arranged unsignaled delays of reinforcement. Responses during the nominal unsignaled delay periods had no effect on the reinforcer presentations. In Experiment 1, the unsignaled delays were studied using variable-interval schedules as baselines. Relative to the immediate reinforcement condition, 0.5-s unsignaled delays decreased the duration of the reinforced interresponse times and increased the overall frequency of short (<0.5-s) interresponse times. Longer, 5.0-s unsignaled delays increased the duration of the reinforced interresponse times and decreased the overall frequency of the short interresponse times. In Experiment 2, similar effects to those of Experiment 1 were obtained when the 0.5-s unsignaled delays were imposed upon a baseline schedule that explicitly arranged reinforcement of short interresponse times and therefore already generated a large number of short interresponse times. The results support earlier suggestions that the unsignaled 0.5-s delays change the functional response unit from a single key peck to a multiple key-peck unit. These findings are discussed in terms of the mechanisms by which contingencies control response structure in the absence of specific structural requirements.     

A nonparametric approach for assessing latent trait unidimensionality

Assuming a nonparametric family of item response theory models, a theory-based procedure for testing the hypothesis of unidimensionality of the latent space is proposed. The asymptotic distribution of the test statistic is derived assuming unidimensionality, thereby establishing an asymptotically valid statistical test of the unidimensionality of the latent trait. Based upon a new notion of dimensionality, the test is shown to have asymptotic power 1. A 6300 trial Monte Carlo study using published item parameter estimates of widely used standardized tests indicates conservative adherence to the nominal level of significance and statistical power averaging 81 out of 100 rejections for examinee sample sizes and psychological test lengths often incurred in practice.The referees' comments were remarkably detailed and greatly enhanced the writeup and sensitized the author to certain pertinent issues. Discussions with Fritz Drasgow, Lloyd Humphreys, Dennis Jennings, Brian Junker, Robert Linn, Ratna Nandakumar, and Robin Shealy were also very useful.This research was supported by the Office of Naval Research under grant N00014-84-K-0186; NR 150-533, and by the National Science Foundation under grant DMS 85-03321.     

La balance optimisme/pessimisme : détermination des styles d’expectations envers le futur en se basant sur la bidimensionnalité du Life Orientation Test–Revised

IntroductionSince the 1980s, two major conceptions of the representation of optimism and pessimism have been disputed: a unidimensional structure and a bidimensional structure.ObjectiveThe bidimensional properties of the LOT-R in French are further explored in order to determine the styles of expectations towards the future according to the levels of optimism and pessimism.MethodA study carried out on a sample of 913 adults from France (72.7% women, M = 41.14 years) proposes (1) to analyze the factorial structure of the instrument, the relationship between the two constructs as well as their separability, (2) to explore the styles of expectations according to the levels of positive and negative expectations by latent profile analysis, (3) to study the influence of socio-demographic factors (age, sex, socio-professional category) on cognitive expectations about the future.ResultsThe confirmatory factor analyzes establish the replicability of the bidimensional latent structure of the instrument across age and gender groups, with the separability between the two constructs increasing with advancing age. The latent profile analysis supports the existence of three styles of expectations towards the future within the sample: the optimistic style, the mixed style and the pessimistic style. The MIMIC model demonstrates that increasing age and socio-professional category are determinants of levels of optimism and pessimism as well as of expectation styles.ConclusionThis research makes it possible to use the styles of expectations towards the future which empirically models the balance between the levels of optimism and pessimism.     

Argument as a formulation-decision-decision... sequence

Problems with regard to the analysis of argumentative partly discourse arise from definitorial disconformity. In this article, Informal argument is taken as the primary definition to study the basic structure of argument from a fragment of an Agatha Christie novel. Bilmes' account of the notions of Formulation (F) and Decision (D+/D-) are adapted to describe the relations of opposition which are displayed in informal argument. The minimal structure of argument is represented by the formula F/D-/D-, in which F is a speaker's personal composition of a fact, the first D- is the disconfirming uptake of it by another speaker and the second D- is the completing disconfirming uptake by the initial speaker. Some of the speaker's possibilities to initiate an argument by expressing a Formulation are explored, as well as the social and cultural norms which play a role in argument-initiation and the concepts of win and loss.     

从情绪描述看青少年期到成人期认知结构的发展

该研究依据研究者制定的认知发展水平评价系统,对年龄范围在13—55岁之间的90名被试关于生气、害怕、伤心、高兴四种情绪的自我描述进行了评价分析。结果表明,青少年期的思维具有形式化、外在、抽象等特点,成人期的思维具有内在、具体、形象等特点,前者具有刻板性、封闭性,后者具有灵活性、开放性。     

Interpreting canonical correlation analysis through biplots of structure correlations and weights

This paper extends the biplot technique to canonical correlation analysis and redundancy analysis. The plot of structure correlations is shown to the optimal for displaying the pairwise correlations between the variables of the one set and those of the second. The link between multivariate regression and canonical correlation analysis/redundancy analysis is exploited for producing an optimal biplot that displays a matrix of regression coefficients. This plot can be made from the canonical weights of the predictors and the structure correlations of the criterion variables. An example is used to show how the proposed biplots may be interpreted.     

Finite mixtures in confirmatory factor-analysis models

In this paper, various types of finite mixtures of confirmatory factor-analysis models are proposed for handling data heterogeneity. Under the proposed mixture approach, observations are assumed to be drawn from mixtures of distinct confirmatory factor-analysis models. But each observation does not need to be identified to a particular model prior to model fitting. Several classes of mixture models are proposed. These models differ by their unique representations of data heterogeneity. Three different sampling schemes for these mixture models are distinguished. A mixed type of the these three sampling schemes is considered throughout this article. The proposed mixture approach reduces to regular multiple-group confirmatory factor-analysis under a restrictive sampling scheme, in which the structural equation model for each observation is assumed to be known. By assuming a mixture of multivariate normals for the data, maximum likelihood estimation using the EM (Expectation-Maximization) algorithm and the AS (Approximate-Scoring) method are developed, respectively. Some mixture models were fitted to a real data set for illustrating the application of the theory. Although the EM algorithm and the AS method gave similar sets of parameter estimates, the AS method was found computationally more efficient than the EM algorithm. Some comments on applying the mixture approach to structural equation modeling are made.Note: This paper is one of the Psychometric Society's 1995 Dissertation Award papers.—EditorThis article is based on the dissertation of the author. The author would like to thank Peter Bentler, who was the dissertation chair, for guidance and encouragement of this work. Eric Holman, Robert Jennrich, Bengt Muthén, and Thomas Wickens, who served as the committee members for the dissertation, had been very supportive and helpful. Michael Browne is appreciated for discussing some important points about the use of the approximate information in the dissertation. Thanks also go to an anonymous associate editor, whose comments were very useful for the revision of an earlier version of this article.     

Shrinkage estimation of linear combinations of true scores

This paper is concerned with combining observed scores from sections of tests. It is demonstrated that in the presence of population information a linear combination of true scores can be estimated more efficiently than by the same linear combination of the observed scores. Three criteria for optimality are discussed, but they yield the same solution which can be described and motivated as a multivariate shrinkage estimator.Input from Eric Bradlow, Charles Lewis, and Linda Zeger is acknowledged. Research for this paper was funded by the Program Research Council (ETS). Suggestions of the Editor and of anonymous referees were instrumental in several improvements of the paper.     

计量测验效度的一种方法——测量目标结构空间的实证性因素分析

该文提出了计量测验效度的一种统一方法。首先,根据测量目标由测验编制者提出一组可能的线性拟合模型,拟合模型的集合称作“测量目标结构空间”。然后运用实证性因素分析对各个假设的拟合模型进行多方面的拟合良好性检验。若其中的某一假设模型能最优地拟合预测资料,则该模型中的公共因素的方差总贡献与观测变量的总方差的比就可定义为该测验的效度     

Residualanalysis in the polytomous rasch model

Residuals for check of model fit in the polytomous Rasch model are examined. Comparisons are made between using counts for all response pattern and using item totals for score groups for the construction of the residuals. Comparisons are also, for the residuals based on score group totals, made between using as basis the item totals, or using the estimated item parameters. The developed methods are illustrated by two examples, one from a psychiatric rating scale, one from a Danish Welfare Study.