The generalized Logit-Linear Item Response Model for Binary-Designed Items

This paper introduces the generalized logit-linear item response model (GLLIRM), which represents the item-solving process as a series of dichotomous operations or steps. The GLLIRM assumes that the probability function of the item response is a logistic function of a linear composite of basic parameters which describe the operations, and the coefficients depend on three design matrices X, Y and Z. The GLLIRM provides a tool for testing hypotheses on the item-solving process and generalizes existing models. An empirical application is included, in which the model is applied to evaluate sources of difficulty and pairwise item interactions in a logical analysis test. This research was supported by the Comunidad de Madrid grant CCG06-UAM/ESP-0043.     

Proof Systems for Reasoning about Computation Errors

In the paper we examine the use of non-classical truth values for dealing with computation errors in program specification and validation. In that context, 3-valued McCarthy logic is suitable for handling lazy sequential computation, while 3-valued Kleene logic can be used for reasoning about parallel computation. If we want to be able to deal with both strategies without distinguishing between them, we combine Kleene and McCarthy logics into a logic based on a non-deterministic, 3-valued matrix, incorporating both options as a non-deterministic choice. If the two strategies are to be distinguished, Kleene and McCarthy logics are combined into a logic based on a 4-valued deterministic matrix featuring two kinds of computation errors which correspond to the two computation strategies described above. For the resulting logics, we provide sound and complete calculi of ordinary, two-valued sequents. Presented by Yaroslav Shramko and Heinrich Wansing     

Neuropsychological differentiation of progressive aphasic disorders

The differentiation of subtypes of primary progressive aphasia (PPA) remains challenging. We aimed to identify optimum neuropsychological measures for characterizing PPA, to examine the relationship between behavioural change and subtypes of PPA and to determine whether characteristic profiles of language, working memory, and behavioural changes occur in PPA. Forty-seven patients with PPA and multi-domain Alzheimer's disease (AD) together with 19 age-matched controls underwent a large battery of working memory and language tests. We found that simple tasks of sentence ordering, narrative production, and buccofacial praxis were particularly useful in differentiating non-fluent/agrammatic variant PPA (nfvPPA) from other PPA subtypes, whereas a test of single word comprehension was useful in detecting semantic dementia (SD). No individual tests were discriminating for logopenic variant PPA (lvPPA) relative to nfvPPA. LvPPA and multidomain AD exhibited similar language profiles. A principal components analysis revealed that characteristic PPA profiles extended beyond the realms of language, in particular, the presence of apraxia in nfvPPA, behavioural changes in SD, and working memory deficits in lvPPA. These findings suggest that not all tests are equally discriminatory for PPA and highlight the importance of a test profile in differentiating PPA. These results also support the view that lvPPA is a focal form of AD and emphasize the difficulties classifying lvPPA.     

Development and Evaluation of a Decision Aid About Prenatal Testing for Women of Advanced Maternal Age

Objective: To develop and evaluate a decision aid designed to prepare patients of advanced maternal age for counseling about prenatal diagnostic testing. Setting: A regional genetics center. Design: A before/after study. Interventions: Participants used an audioguided workbook to learn about options and outcomes and to clarify personal risks, values, questions, and predispositions. Subjects: 21 women of advanced maternal age and 17 spouses. Main outcome measures: Knowledge of prenatal testing alternatives, decisional conflict, level of anxiety, and acceptability of the decision aid. Results: After using the decision aid, participants had significantly reduced decisional conflict (uncertainty) and a significant increase in knowledge. There was no effect on state or trait anxiety. More than three-quarters of participants were satisfied with the length, clarity, balance, and acceptability of the decision aid. Conclusions: The decision aid shows promise as a useful aid for preparing couples for counseling.     

Psychosocial Issues That Face Patients With Charcot-Marie-Tooth Disease: The Role of Genetic Counseling

Charcot-Marie-Tooth (CMT) disease is a hereditary debilitating progressive muscular atrophy and sensory neuropathy of the distal extremities. CMT is usually nonlife threatening. Signs of the disease usually present in childhood or in young adulthood and the level of disability can be variable within and between families. Research addressing specific psychosocial and emotional issues faced by individuals with CMT is limited. Fourteen adults with a clinical and/or molecular diagnosis of CMT (ages 32–74 years) consented to an audio taped interview. The format of the interview was based around an informal questionnaire to prompt and guide the interviewee to describe their experiences of living with a disabling genetic disorder. The interviews focused on their experiences of first symptoms and diagnosis, their life experience with CMT, their limitations due to disability and the role of genetic counseling. This study identifies and explores life issues that individuals with CMT may face, specifically grief over the loss of independence, emotional pain and stress such as embarrassment and guilt of passing on a gene mutation, impact on quality of life, the impact of wearing orthopedic devices, and fear of progressive disability. Our findings suggest that that there are emotional and psychosocial issues specific to affected individuals at different life stages and genetic counselors need to be aware of these issues in order to provide age appropriate support and advice to individuals affected by CMT.     

When can we trust theF-approximation of the box-test?

Consider a multivariate context withp variates andk independent samples, each of sizen. To test equality of thek population covariance matrices, the likelihood ratio test is commonly employed. Box'sF-approximation to the null distribution of the test statistic can be used to computep-values, if sample sizes are not too small. It is suggested to regard theF-approximation as accurate if the sample sizesn are greater than or equal to 1+0.0613p ²+2.7265p-1.4182p ^0.5+0.235p ^1.4* In (k), for 5p30,k20.This research was supported by the Deutsche Forschungsgemeinschaft through Ste 405/2-1.     

A novel argument for the Universality of Parsing principles

Previous work on Relative Clause attachment has overlooked a crucial grammatical distinction across both the languages and structures tested: the selective availability of Pseudo Relatives. We reconsider the literature in light of this observation and argue that, all else being equal, local attachment is found with genuine Relative Clauses and that non-local attachment emerges when their surface identical imposters, Pseudo Relatives, are available. Hence, apparent cross-linguistic variation in parsing preferences is reducible to grammatical factors. The results from two novel experiments in Italian are presented in support of these conclusions.