Fitting direct covariance structures by the MSTRUCT modeling language of the CALIS procedure

This paper demonstrates the usefulness and flexibility of the general structural equation modelling (SEM) approach to fitting direct covariance patterns or structures (as opposed to fitting implied covariance structures from functional relationships among variables). In particular, the MSTRUCT modelling language (or syntax) of the CALIS procedure (SAS/STAT version 9.22 or later: SAS Institute, 2010) is used to illustrate the SEM approach. The MSTRUCT modelling language supports a direct covariance pattern specification of each covariance element. It also supports the input of additional independent and dependent parameters. Model tests, fit statistics, estimates, and their standard errors are then produced under the general SEM framework. By using numerical and computational examples, the following tests of basic covariance patterns are illustrated: sphericity, compound symmetry, and multiple‐group covariance patterns. Specification and testing of two complex correlation structures, the circumplex pattern and the composite direct product models with or without composite errors and scales, are also illustrated by the MSTRUCT syntax. It is concluded that the SEM approach offers a general and flexible modelling of direct covariance and correlation patterns. In conjunction with the use of SAS macros, the MSTRUCT syntax provides an easy‐to‐use interface for specifying and fitting complex covariance and correlation structures, even when the number of variables or parameters becomes large.     

A general proof of consistency of heuristic classification for cognitive diagnosis models

The Asymptotic Classification Theory of Cognitive Diagnosis (Chiu et al., 2009, Psychometrika, 74, 633–665) determined the conditions that cognitive diagnosis models must satisfy so that the correct assignment of examinees to proficiency classes is guaranteed when non‐parametric classification methods are used. These conditions have only been proven for the Deterministic Input Noisy Output AND gate model. For other cognitive diagnosis models, no theoretical legitimization exists for using non‐parametric classification techniques for assigning examinees to proficiency classes. The specific statistical properties of different cognitive diagnosis models require tailored proofs of the conditions of the Asymptotic Classification Theory of Cognitive Diagnosis for each individual model – a tedious undertaking in light of the numerous models presented in the literature. In this paper a different way is presented to address this task. The unified mathematical framework of general cognitive diagnosis models is used as a theoretical basis for a general proof that under mild regularity conditions any cognitive diagnosis model is covered by the Asymptotic Classification Theory of Cognitive Diagnosis.     

Looking ahead from age 6 to 13: A deeper insight into the development of planning ability

Planning ability gradually increases throughout childhood. However, it remains unknown whether this is attributable to global factors such as an increased ability and willingness to inhibit premature, impulsive responding, or due to the availability of specific planning operations, such as being able to mentally plan ahead more steps (‘search depth’) or to derive a clear temporal order of goals by the task layout (‘goal hierarchy’). Here, we studied the development of planning ability with respect to these global and problem‐specific aspects (search depth and goal hierarchy) of performance in 178 children from 6 to 13 years using the Tower of London task. As expected, global performance gradually developed with age. In accordance, planning durations increasingly reflected global problem demands with longer pre‐planning in harder problems. Furthermore, specific planning parameters revealed that children were increasingly capable of mentally searching ahead more steps. In contrast, the ability to derive a goal hierarchy did not show age‐related changes. While the global development of planning performance and adaptive planning durations were proposed to primarily reflect enhanced self‐monitoring, the specific increase in search depth across childhood that most likely proceeds until young adult age represents more directly planning‐related processes. Thus, development of planning ability is supported by multiple contributions.     

Positive vs. negative switching barriers: the influence of service consumers' need for variety

• In this study, we deal with the existing debate related to the establishment of switching barriers retaining customers in the relationship with a provider. In particular, we demonstrate that ‘positive’ switching barriers (relational benefits) play a greater role that the ‘negative’ ones (switching costs and availability and attractiveness of other providers' offers) in determining customer satisfaction and retention. On the other hand, we include customers' need for variety in the proposed model, in order to demonstrate that a higher level of this psychological trait will lead to a lower perception of the existence of switching barriers. The hypotheses proposed have been tested for a services context on a sample of 800 individuals, using the technique ‘Partial Least Squares’ (PLS). Our findings lead to some interesting managerial implications.

Copyright © 2006 John Wiley & Sons, Ltd.     

How is the therapeutic relationship talked into being?

A review of the place of the therapeutic relationship within systemic approaches to therapy is provided. This serves to contextualize the findings of a research study that subjects therapy sessions to a discursive analysis. The purpose of the analysis is to learn more about the therapeutic relationship through an examination of what actually takes place in sessions. Moments in therapy where therapeutic engagement is stronger and moments when it is weaker are identified and analysed. The discursive contours of a robust therapeutic relationship are highlighted. A theoretical account of the constituents of a stronger therapeutic relationship is constructed from this analysis.

相似文献   

Socioeconomic status in childhood and adulthood: associations with dispositional optimism and pessimism over a 21-year follow-up

We examined whether dispositional optimism and pessimism (overall LOT-R and optimism and pessimism component scores) of 694 adults aged 24 and 27 were associated with socioeconomic status (SES) measured concurrently and in childhood at ages 3 and 6. SES measures included education, occupational status and unemployment, and income. Concurrent adulthood SES was associated with the overall LOT-R and optimism and the pessimism component scores. Childhood family SES predicted overall LOT-R and pessimism component scores, even after controlling statistically for the adulthood SES. Social mobility between SES of family of origin and current SES also influenced the scores. The current findings suggest that the foundation of dispositional optimism and pessimism is related to early SES of the family.     

Trait emotional intelligence profiles of students from different university faculties

This study investigated the trait emotional intelligence (trait EI or trait emotional self‐efficacy) profiles of 512 students from five university faculties: technical studies, natural sciences, social sciences, arts, and humanities. Using the Trait Emotional Intelligence Questionnaire, it was hypothesised that (a) social sciences would score higher than technical studies in Emotionality, (b) arts would score higher than technical studies in Emotionality, (c) arts would score lower than technical studies in Self‐control, and (d) there would be an interaction between gender and faculty, whereby female students would score higher than male students within the social sciences only. Several other exploratory comparisons were also performed. Results supported hypotheses (a), (b), and (d), but not hypothesis (c), although the differences were in the predicted direction.     

Corporeal awareness and proprioceptive sense of the phantom

Phantom limb perception almost invariably follows limb amputation, and can be characterized by various corporeal and proprioceptive qualities. We report a study of 283 amputees, which administered a structured questionnaire to systematically determine the relative frequency and nature of various bodily aspects of phantom limb perception. These include the size, shape, posture, and telescoping of the phantom; exteroceptive sensations of itch, touch, pressure, vibration, temperature, and ‘electric’ sensations; and prosthesis embodiment. Phantom limbs were generally found to be characterized by properties that parallel those of the intact body, although with anatomically impossible configurations sometimes being perceived. We suggest that both the internal limb image and limb schemata play a significant role in the continued perception of phantom limbs.     

Two simple approximations to the distributions of quadratic forms

Many test statistics are asymptotically equivalent to quadratic forms of normal variables, which are further equivalent to with z_i being independent and following N(0,1). Two approximations to the distribution of T have been implemented in popular software and are widely used in evaluating various models. It is important to know how accurate these approximations are when compared to each other and to the exact distribution of T. The paper systematically studies the quality of the two approximations and examines the effect of the λ_i and the degrees of freedom d by analysis and Monte Carlo. The results imply that the adjusted distribution for T can be as good as knowing its exact distribution. When the coefficient of variation of the λ_i is small, the rescaled statistic is also adequate for practical model inference. But comparing T_R against will inflate type I errors when substantial differences exist among the λ_i, especially, when d is also large.