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.     

Some neglected problems in IRT

The paper addresses three neglected questions from IRT. In section 1, the properties of the “measurement” of ability or trait parameters and item difficulty parameters in the Rasch model are discussed. It is shown that the solution to this problem is rather complex and depends both on general assumptions about properties of the item response functions and on assumptions about the available item universe. Section 2 deals with the measurement of individual change or “modifiability” based on a Rasch test. A conditional likelihood approach is presented that yields (a) an ML estimator of modifiability for given item parameters, (b) allows one to test hypotheses about change by means of a Clopper-Pearson confidence interval for the modifiability parameter, or (c) to estimate modifiability jointly with the item parameters. Uniqueness results for all three methods are also presented. In section 3, the Mantel-Haenszel method for detecting DIF is discussed under a novel perspective: What is the most general framework within which the Mantel-Haenszel method correctly detects DIF of a studied item? The answer is that this is a 2PL model where, however, all discrimination parameters are known and the studied item has the same discrimination in both populations. Since these requirements would hardly be satisfied in practical applications, the case of constant discrimination parameters, that is, the Rasch model, is the only realistic framework. A simple Pearsonx ² test for DIF of one studied item is proposed as an alternative to the Mantel-Haenszel test; moreover, this test is generalized to the case of two items simultaneously studied for DIF.     

Social integration and social support in a life crisis: Effects of macrosocial change in east Germany

This process evaluation study examined what variables moderate and mediate treatment effects on days in stable housing and client satisfaction for homeless mentally ill clients. In general, demographic characteristics did not moderate either outcome variable. Housing contacts, entitlement contacts, mental health contacts, and supportive services were significant mediators of the treatment effect on days in stable housing. Program contacts, mental health contacts, and supportive services were significant mediators of client satisfaction. The authors thank the National Institute of Mental Health for their financial support (MH43248, MH42357) for this project, Dorothy Gano for word processing and editorial assistance, and Gitry Heydebrand, Melissa Dannelet, Betty Tempelhoff, Ruth Smith, and Laeeq Ahmad for assisting in the interviews of clients. We are also appreciative of the cooperation given to us by the staffs of Malcolm Bliss Mental Health Center, St. Patrick's Center, the Community Advocacy and Support Alliance Program, and the St. Louisemergency shelters. Finally, we thank all of the participants in this study; we hope that their homelessness has now ended. (The conclusions presented in this paper are the sole responsibility of the authors and do not necessarily reflect official National Institute for Mental Health policy.)     

Identification of inconsistent variates in factor analysis

When some of observed variates do not conform to the model under consideration, they will have a serious effect on the results of statistical analysis. In factor analysis the model with inconsistent variates may result in improper solutions. In this article a useful method for identifying a variate as inconsistent is proposed in factor analysis. The procedure is based on the likelihood principle. Several statistical properties such as the effect of misspecified hypotheses, the problem of multiple comparisons, and robustness to violation of distributional assumptions are investigated. The procedure is illustrated by some examples.     

An extension of the partial credit model with an application to the measurement of change

The partial credit model is considered under the assumption of a certain linear decomposition of the item × category parameters _ih into basic parameters _j. This model is referred to as the linear partial credit model. A conditional maximum likelihood algorithm for estimation of the j is presented, based on (a) recurrences for the combinatorial functions involved, and (b) using a quasi-Newton approach, the so-called Broyden-Fletcher-Goldfarb-Shanno (BFGS) method; (a) guarantees numerically stable results, (b) avoids the direct computation of the Hesse matrix, yet produces a sequence of certain positive definite matricesB _k ,k=1, 2, ..., converging to the asymptotic variance-covariance matrix of the . The practicality of these numerical methods is demonstrated both by means of simulations and of an empirical application to the measurement of treatment effects in patients with psychosomatic disorders.The authors thank one anonymous reviewer for his constructive comments. Moreover, they thankfully acknowledge financial support by the Österreichische Nationalbank (Austrian National Bank) under Grant No. 3720.     

解题策略的同质性和线性逻辑斯谛模型的拟合

为探讨线性逻辑斯谛模型（ＬＬＴＭ）的拟合条件及其和解题策略同质性之间的关系,让被试比较两个负整数指数幂的大小,发现全体被试的数据不能与拉希模型及ＬＬＴＭ相拟合。把被试按其解题策略分成不同策略组后,同一策略组被试的数据可以拟合于拉希模型,但对于ＬＬＴＭ,同一策略组的数据中部分项目的拟合较好,另外一些项目的拟合较差。这一结果表明,解题策略的同质性是ＬＬＴＭ拟合的必要条件,但还不是充分条件。     

激励理论及其综合模型的新发展

激励是组织行为学的一个重要研究领域。本文概述了传统的激励理论、满意感理论在近年的研究新成果和新动向,并对激励理论的三大综合模型(聚合模型、新范式模型和混合模型)作了分析。最后提出了未来激励研究的四个方向。     

Teamwork makes the dream work: Testing for shared perceptions on psycho-behavioural skills between athletes,coaches and parents

Psycho-behavioural skills play a key role in optimising progression through talent development, and this study investigated to what extent athlete’s self-perceptions align with those of their coaches and parents. Firstly, we examined if levels of alignment between these three raters differ across age of the athlete. To this end, 122 athletes between 9 and 18 years old (12.17 ± 2.41 years old; 47 gymnasts, 13 cyclists and 62 badminton players) completed a psycho-behavioural questionnaire. The ANOVA’s indicated low levels of correspondence between the ratings of the athlete, the coach and the parents during childhood, while better levels of shared perceptions were found in adolescence. Secondly, we investigated to what extent coaches and parents believed their own perception of the athlete’s and the perception of the athlete’s psycho-behavioural skills were accurate. Parents appeared to be more confident in accurately perceiving the psycho-behavioural skills of the athlete than coaches. Parents and coaches also believed that older athletes would be more honest on their psycho-behavioural shortcomings than younger athletes. Altogether, these findings highlight that athletes and other stakeholders in the talent development environment should strive for better alignment in perceptions on psycho-behavioural skills during the talent development pathway. With better integrated perceptions, a more functional and efficient talent development system for the athlete targeting the psycho-behavioural skills can be created.     

Specific and general transfer of perceptual-motor skills and learning between sports: A systematic review

ObjectivesSport developmental models contend that participating in different sports promotes expertise development, implying positive skill transfer between sports. This study conceptualizes and examines how specific and general transfer occur and interact between sports in the short- (skill transfer) and long-term (learning transfer). Specific transfer is predicated on the perception and utilisation of specifying information in a transfer task, while general transfer relies on non-specifying, "general" information. Furthermore, the study examined how certain conditions (affordance similarity, perceptual-motor exploration and expertise) promote the transfer process.DesignSystematic literature review.MethodsAn electronic search was performed on SPORTDiscuss, Pubmed/MEDLINE, and Scopus. Studies were included if participants performed a transfer task in a sport different to the sport they learned a skill in.ResultsA total of 17 studies of low-to-moderate quality were included. Most studies showed specificity of transfer between sports with overlapping affordances and generality of transfer between sports with no overlapping affordances (for a given skill). Only 2 studies examined how perceptual-motor exploration supported specific transfer, and 2 examined transfer for (subsequent) learning with contrasting results. Six studies indicated an expertise effect, showing higher transfer in skilled vs less-skilled athletes.ConclusionsThis review provides a conceptualization of specificity and generality of transfer, and initial evidence on how transfer emerges between sports in the short-term. It provides little information on the general-specific interaction in the short-term, and does not provide any insights on how transfer emerges in mid- and long-term. As such, no inference regarding sport developmental models can be made. The low-to-moderate quality of the studies requires caution in interpreting these findings. We encourage future research to investigate general and specific transfer longitudinally, recruiting populations with different expertise levels to further advance our current understanding.     

Resistance To Change As A Function Of Stimulus-reinforcer And Location-reinforcer Contingencies

Pigeons responded on two keys in each component of a multiple concurrent schedule. In one series of conditions the distribution of reinforcers between keys within one component was varied so as to produce changes in ratios of reinforcer totals for key locations when summed across components. In a second series, reinforcer allocation between components was varied so as to produce changes in ratios of reinforcer totals for components, summed across key locations. In each condition, resistance to change was assessed by presenting response-independent reinforcers during intercomponent blackouts and (for the first series) by extinction of responding on both keys in both components. Resistance to change for response totals within a component was always greater for the component with the larger total reinforcer rate. However, resistance to change for response totals at a key location was not a positive function of total reinforcement for pecking that key; indeed, relative resistance to extinction for the two locations showed a weak negative relation to ratios of reinforcer totals for key location. These results confirm the determination of resistance to change by stimulus—reinforcer contingencies.