Data-driven Q-matrix validation using a residual-based statistic in cognitive diagnostic assessment

In a cognitive diagnostic assessment (CDA), attributes refer to fine-grained knowledge points or skills. The Q -matrix is a central component of CDA, which specifies the relationship between items and attributes. Oftentimes, attributes and Q -matrix are defined by subject-matter experts, and assumed to be appropriate without any misspecifications. However, this assumption does not always hold in real applications. To address this concern, this paper proposes a residual-based statistic for validating the Q -matrix. Its performance is evaluated in a simulation study and compared against that of an existing method proposed in Liu, Xu and Ying (2012, Applied Psychological Measurement, 36, 548). Simulation results indicate that the proposed method leads to a higher recovery rate of the Q -matrix and is computationally more efficient. The advantage in computational efficiency is particularly pronounced when the number of attributes measured by the test reaches five or more. Results also suggest that the two methods have different tendencies in estimating the attribute vector for each item. In cases where the methods fail to recover the correct Q -matrix, the method in Liu et al. (2012, Applied Psychological Measurement, 36, 548) tends to overestimate the number of attributes measured by the items, whereas our method does not show that bias.     

台湾人工生殖技术管制之回顾与前瞻

台湾地区人工生殖技术的管制先后经历了道德管制和行政管制两个阶段,目前正积极总结各阶段管制模式的成败得失,努力构造《人工生殖法》的原则和框架,以提高人工生殖技术管制的合法性和有效性。     

A Bayesian analysis of finite mixtures in the LISREL model

In this paper, we propose a Bayesian framework for estimating finite mixtures of the LISREL model. The basic idea in our analysis is to augment the observed data of the manifest variables with the latent variables and the allocation variables. The Gibbs sampler is implemented to obtain the Bayesian solution. Other associated statistical inferences, such as the direct estimation of the latent variables, establishment of a goodness-of-fit assessment for a posited model, Bayesian classification, residual and outlier analyses, are discussed. The methodology is illustrated with a simulation study and a real example.This research was supported by a Hong Kong UGC Earmarked grant CUHK 4026/97H. The authors are indebted to the Editor, the Associate Editor, and three anonymous reviewers for constructive comments in improving the paper, and also to ICPSR and the relevant funding agency for allowing the use of the data. The assistance of Michael K.H. Leung and Esther L.S. Tam is gratefully acknowledged.     

Cognitive Behavioral Therapy for PTSD: The Role of Complex PTSD on Treatment Outcome

Posttraumatic stress disorder (PTSD) represents an often chronic and debilitating mental illness resulting from exposure to trauma. Although the most compelling evidence for the treatment of PTSD is cognitive behavioral therapy (CBT), many patients experience residual functional impairment, or relapse, suggesting that this approach does not work for all cases of PTSD. Repeated severe trauma, particularly during development, might increase the risk for a more intricate clinical profile, called complex PTSD (CPTSD), which might contribute to poorer treatment response. The following provides a comprehensive summary of the evidence examining whether CPTSD symptomatology is related to poorer treatment outcome of CBT, reviews the literature on the treatment of CPTSD, and offers insights into current issues and future directions of the construct.     

Parental refusals of medical treatment: the harm principle as threshold for state intervention

Minors are generally considered incompetent to provide legally binding decisions regarding their health care, and parents or guardians are empowered to make those decisions on their behalf. Parental authority is not absolute, however, and when a parent acts contrary to the best interests of a child, the state may intervene. The best interests standard is the threshold most frequently employed in challenging a parent's refusal to provide consent for a child's medical care. In this paper, I will argue that the best interest standard provides insufficient guidance for decision-making regarding children and does not reflect the actual standard used by medical providers and courts. Rather, I will suggest that the Harm Principle provides a more appropriate threshold for state intervention than the Best Interest standard. Finally, I will suggest a series of criteria that can be used in deciding whether the state should intervene in a parent's decision to refuse medical care on behalf of a child.     

Kinetics of the persistent photocurrent in semiconductors: a case example for amorphous chalcogenides

Although the persistent photocurrent or the residual photocurrent decay (RPD) in photoconductive semiconductors is known to be dominated by dispersive recombination kinetics which produce the stretched exponential functional decay, exp(-Ct^β), where β (<1.0) is the dispersion parameter, the reason for the occurrence of the RPD is still not clear. We discuss the origin of the dispersive nature of long-term photocurrent decay in amorphous chalcogenides (a-Chs) as a case example. The slow recombination path of excess photocarriers in a-Chs can be attributed to their characteristic feature of negative-U defects at which lattice relaxation with multiphonon process may play a role.     

Introspection and subliminal perception

Subliminal perception (SP) is today considered a well-supported theory stating that perception can occur without conscious awareness and have a significant impact on later behaviour and thought. In this article, we first present and discuss different approaches to the study of SP. In doing this, we claim that most approaches are based on a dichotomic measure of awareness. Drawing upon recent advances and discussions in the study of introspection and phenomenological psychology, we argue for both the possibility and necessity of using an elaborated measure of subjective states. In the second part of the article, we present findings where these considerations are implemented in an empirical study. The results and implications are discussed in detail, both with reference to SP, and in relation to the more general problem of using elaborate introspective reports as data in relation to studies of cognition.     

The association between retrospective outcome evaluations and pre-post-treatment changes in psychodynamic group-psychotherapy

In the present study of 203 patients in psychodynamic group psychotherapy, we explore associations between patient and therapist global retrospective outcome evaluations (ROE), and pre-post-treatment changes on the Symptom Check List 90 Revised (SCL-90-R) and non-symptomatic focus of therapy. There were no significant associations between ROE, diagnoses and demographic variables, and pre-treatment SCL-90-R associations were negligible (less than 4% of overlapping variance). SCL-90-R subscale improvement expressed as residual gain score explained the overall largest percent of variance in both patients and therapists (44% and 25%, respectively) when compared with raw difference scores (32% and 18%), and percent reduction from baseline (34% and 23%). Moreover, ROE/end-state adjustment associations were substantial (42% and 24%). Therapists' evaluation of change showed the strongest association with improvement in non-symptomatic focus of therapy, while patients' evaluation had the strongest association with improvement in SCL-Depression. It is concluded that retrospective evaluations reflect changes related to treatment. However, unexplained variance may be independent of symptomatic state, and associated with personality factors or domains not captured by standard questionnaires.     

代孕技术的伦理与法律思考

简要介绍了代孕的概念,指出了在我国有条件开放代孕的合理性。从家庭关系、子宫工具化和婴儿商业化三个方面给出了代孕合理性的伦理依据。从合同法、身体权、生育权三个方面给出了法律的解读。从伦理与法律两方面对我国有条件的开放代孕加以论述,并提出相应对策及理论支持。     

Accounting for individual differences in speed in the discretized signed residual time model

With advances in computerized tests, it has become commonplace to register not just the accuracy of the responses provided to the items, but also the response time. The idea that for each response both response accuracy and response time are indicative of ability has explicitly been incorporated in the signed residual time (SRT) model (Maris & van der Maas, 2012, Psychometrika, 77, 615–633), which assumes that fast correct responses are indicative of a higher level of ability than slow correct responses. While the SRT model allows one to gain more information about ability than is possible based on considering only response accuracy, measurement may be confounded if persons show differences in their response speed that cannot be explained by ability, for example due to differences in response caution. In this paper we propose an adapted version of the SRT model that makes it possible to model person differences in overall speed, while maintaining the idea of the SRT model that the speed at which individual responses are given may be indicative of ability. We propose a two-dimensional SRT model that considers dichotomized response time, which allows one to model differences between fast and slow responses. The model includes both an ability and a speed parameter, and allows one to correct the estimates of ability for possible differences in overall speed. The performance of the model is evaluated through simulation, and the relevance of including the speed parameter is studied in the context of an empirical example from formative educational assessment.