Continuous and discrete latent structure models for item response data

Relations are examined between latent trait and latent class models for item response data. Conditions are given for the two-latent class and two-parameter normal ogive models to agree, and relations between their item parameters are presented. Generalizationss are then made to continuous models with more than one latent trait and discrete models with more than two latent classes, and methods are presented for relating latent class models to factor models for dichotomized variables. Results are illustrated using data from the Law School Admission Test, previously analyzed by several authors.     

Food and amphetamine self-administration by baboons: effects of alternatives.

The effects of the availability of an alternative reinforcer on responding maintained by food pellets or fluid solutions were examined in 6 adult male baboons (Papio cynocephalus anubis). During daily 23-hr experimental sessions, baboons had concurrent access to both food pellets and fluid, with responding maintained under fixed-ratio schedules of reinforcement that varied between the two commodities. The fixed-ratio requirement, or cost, for pellets was increased when (a) no fluid, (b) a dilute dextrose vehicle, (c) 0.002 mg/kg d-amphetamine, or (d) 0.004 mg/kg d-amphetamine was available. When given nonrestricted concurrent access to food pellets and amphetamine at minimal cost (FR 2), baboons self-administered sufficient amphetamine to decrease pellet intake. Increasing the response requirement for pellets decreased pellet intake at a similar rate regardless of the available fluid and increased fluid intake in a variable manner among baboons such that there were no statistically significant increases in fluid intake. In contrast, when access to pellets was restricted to 70% of maximal intake under nonrestricted conditions, increasing pellet cost decreased pellet intake and increased fluid intake more rapidly when the high amphetamine dose was available. Thus, amphetamine was more effective as an economic substitute for pellets when access to pellets was restricted. The response cost for vehicle and both amphetamine concentrations was increased when baboons had nonrestricted and restricted access to pellets. Increasing the response requirement for fluid delivery decreased intake of all three fluids similarly under both pellet-access conditions. The results indicate that substitution between commodities with minimal commonalities can be studied under controlled laboratory conditions and is dependent upon reinforcement schedule and commodity restrictions.     

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.     

The Development of the Toddler Behavior Screening Inventory

The purpose of the present study was to develop the Toddler Behavior Screening Inventory (TBSI) for rapidly assessing maternal reports of toddler behavior problems. The TBSI is a 40-item measure intended for use by pediatricians, psychologists, and other child-care professionals. A group of mothers (n = 312) rated the initial 93-item TBSI in terms of behavior frequency and parental perception of the behavior as problematic. Following item elimination, 40 items were retained due to being both frequent and problematic at all toddler age levels. Data were obtained with a new sample of mothers (n = 581) and showed the TBSI to possess good reliability and validity.     

Data Smoothing: Prediction of Human Behavior, Detection of Behavioral Patterns, and Monitoring Treatment Effectiveness in Single-Subject Behavioral Studies

Data-smoothing can be particularly useful in predicting human behavior, detecting behavioral patterns, and monitoring treatment effectiveness in highly variable single-subject behavioral experiments that cannot be determined by only visual inspection of their graphs. Using an example from the applied behavior analytic literature, the use of moving-average and exponential data-smoothing aided the detection of the unique behavioral patterns of a child with autism across different treatments. Furthermore, the utility of the data-smoothing procedures to monitor and control the effectiveness of an intervention is discussed. The ease of their calculations suggest use of data-smoothing by behavior analysts whenever the effects of particular interventions are questionable.     

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     

传统统计方法面临的挑战:元分析方法

利用计算机构造实验组和控制组总体,进行传统统计方法与元分析比较实验研究。在实验组总体高出控制组总体０．５０个标准差的提下,传统ｔ检验的统计检验能力（Ｐ）仅为为４１％;而利用元分析的方法进行统计分析,其结果与计算机构造模型有很高的一致性从而提出元分析方法在进入心理学实验研究和证实理论方面的有效性和可靠性,以及传统统计方法面临挑战的事实。     

Should the behavioral sciences become more pragmatic? The case for functional contextualism in research on human behavior

Although societal need for behavioral science research is enormous, current research practices seem to be inefficient vehicles for producing knowledge that guides practical action. Many of our most popular theories provide little direct guidance for application. They focus on the development of models of the relationships among organismic events such as attitudes, self-efficacy expectations, and behavior, but pay little or no attention to the contextual influences on behavior. Such research is in keeping with a long-standing mechanistic tradition in psychology. We propose a version of contextualism as an alternative paradigm for the behavioral sciences. According to this paradigm, theories and research are evaluated in terms of their contribution to the prediction and influence of behavior. Basic research organized to pursue this goal has a direct bearing on how behavioral phenomena can be changed for practical purposes. Conversely, applied research contributes to basic understanding of the determinants of psychological phenomena.     

Precuing the Target Location in Visual Searching by a Chimpanzee (Pan troglodytes): Effects of Precue Validity

A chimpanzee ( Pan troglodytes ) performed a visual search task using a modified matching-to-sample procedure in which a sample stimulus was followed by the search display, which contained one stimulus identical to the sample (target) and several uniform stimuli different from the sample (distractors). On cued trials, while the subject was observing the sample, a white square (precue) appeared at the location where the target was to be presented (valid trials), or elsewhere (invalid trials). The validity of the precue (correspondence between the cued and the target locations) was changed from 0% to 100% across conditions. Cost-benefit analyses were performed on the difference between valid and noncued trials (benefit) and between invalid and noncued trials (cost). Under the high-validity conditions, the response times were shorter when the cued location corresponded to the target location than when the precue did not appear. When the cued location did not correspond to the target location, on the other hand, the subject took longer to select the target than on noncued trials. When the validity of the precue was relatively low, however, cost of the invalid trials disappeared, while benefit of the valid trials remained. These results confirmed the two-process (automatic and attentional) theory of priming in human information processing; the advance information had the same effects on a chimpanzee's visual search performance as on humans'.     

EMERGENCE OF REINFORCER PREFERENCE AS A FUNCTION OF SCHEDULE REQUIREMENTS AND STIMULUS SIMILARITY

Tustin (1994) recently observed that an individual's preference for one of two concurrently available reinforcers under low schedule requirements (concurrent fixed-ratio [FR] 1) switched to the other reinforcer when the schedule requirements were high (concurrent FR 10). We extended this line of research by examining preference for similar and dissimilar reinforcers (i.e., those affecting the same sensory modality and those affecting different sensory modalities). Two individuals with developmental disabilities were exposed to an arrangement in which pressing two different panels produced two different reinforcers according to progressively increasing, concurrent-ratio schedules. When two dissimilar stimuli were concurrently available (food and a leisure item), no clear preference for one item over the other was observed, regardless of the FR schedules in effect (FR 1, 2, 5, 10, and 20). By contrast, when two similar stimuli were concurrently available (two food items), a clear preference for one item emerged as the schedule requirements were increased from FR 1 to FR 5 or FR 10. These results are discussed in terms of implications for conducting preference assessments and for selecting reinforcers to be used under training conditions in which response requirements are relatively high or effortful.