Optimal Item Calibration for Computerized Achievement Tests

Item calibration is a technique to estimate characteristics of questions (called items) for achievement tests. In computerized tests, item calibration is an important tool for maintaining, updating and developing new items for an item bank. To efficiently sample examinees with specific ability levels for this calibration, we use optimal design theory assuming that the probability to answer correctly follows an item response model. Locally optimal unrestricted designs have usually a few design points for ability. In practice, it is hard to sample examinees from a population with these specific ability levels due to unavailability or limited availability of examinees. To counter this problem, we use the concept of optimal restricted designs and show that this concept naturally fits to item calibration. We prove an equivalence theorem needed to verify optimality of a design. Locally optimal restricted designs provide intervals of ability levels for optimal calibration of an item. When assuming a two-parameter logistic model, several scenarios with D-optimal restricted designs are presented for calibration of a single item and simultaneous calibration of several items. These scenarios show that the naive way to sample examinees around unrestricted design points is not optimal.

     

An improved screw-free method for electrode implantation and intracranial electroencephalographic recordings in mice

We recently developed a glue-based method for the implantation of intracranial electrodes in mice. Our approach is to secure a preconstructed electrode array using a cyanoacrylate-based glue (similar to Krazy Glue). This method is applicable to both young and aging mice and is suitable for long-term electroencephalographic recordings. In the present experiment, we explored whether the glue-based method is capable of securing individual electrodes in addition to securing the electrode array. C57 black mice aged 25–35 days or 13–19 months were operated on under isoflurane anesthesia. Monopolar or bipolar electrodes were inserted independently in the ipsilateral hippocampal CA3 and entorhinal cortical areas, and they were fixed onto the skull using the glue together with dental acrylic, but without anchoring screws. We found that the implanted electrodes were stable and allowed repeat intracranial recordings and electrical stimulation in freely moving mice.     

Student mental health: A pilot study

In this country, little research has been undertaken into the difficulties faced by students and the contributory stressors. It is apparent that they have a lot with which to content. Identification of stressors, assessement of stress levels and consequences on mental health appear vital.A pilot study was undertaken of 40 studets: 10 males aged under 21 years, ten males 21–40 years, 10 females under the age of 21 and 10 females 21–40 years, The purpose was to identify the potential factors leading to student discontent, problems and stress. Students were in the professions allied to medicine. Oral semi-structured interviews and a written questionnaire were used. Results indicated that for students the major difficulties were coursework and emotional state. Finance was a recurring problem but not as troublesome to the students as the other two problems. What must be considered are ways to alleviate student unhappiness. Emphasis should be placed on prevention where possible. Ongoing counseling throughuot the educational years is desirable as are various programmes which address student concerns. Of particular value would be a Student Mental Health Service. ‘Unnecessary’ coursework could be an added burden.     

Mindfulness reduces the correspondence bias

The correspondence bias (CB) refers to the idea that people sometimes give undue weight to dispositional rather than situational factors when explaining behaviours and attitudes. Three experiments examined whether mindfulness, a non-judgmental focus on the present moment, could reduce the CB. Participants engaged in a brief mindfulness exercise (the raisin task), a control task, or an attention to detail task before completing a typical CB measure involving an attitude-attribution paradigm. The results indicated that participants in the mindfulness condition experienced a significant reduction in the CB compared to participants in the control or attention to detail conditions. These results suggest that mindfulness training can play a unique role in reducing social biases related to person perception.     

Memory for how one learned of multiple deaths from AIDS: Repeated exposure and distinctiveness

Studies of memories for the circumstances in which an emotional event was learned of have generally explored isolated, single-occurrence events--for example, the Kennedy assassination. Such factors as the event's distinctiveness, its personal importance, its surprise, the elicited emotional change, and overt rehearsal have been posited as predictors of the memory's vividness and elaborateness. We examined whether these predictor variables would apply to a repeated trauma, using the repeated nature of the trauma to test, in particular, the contribution of distinctiveness. Focusing on the multiple deaths of loved ones from AIDS that many gay men have experienced, we contrasted the vividness and elaborateness of the circumstantial memory of the first death encountered with that of the most recent death, treating distinctiveness as the number of intervening deaths. In an analysis of responses by 80 gay men to a survey, no support was found for the claim that distinctiveness predicts a circumstantial memory's vividness or elaborateness. Only emotional change predicted these characteristics of the memories.     

人口统计、身份和空间:定义美国穆斯林

本文以2001年以来,以美国乔治敦大学穆斯林-基督徒理解中心为基地的《美国公共领域中的穆斯林》项目展开的美国穆斯林民意调查为基础,从人口统计、宗教实践、对社会和政治事务领域各种行为的看法,以及9·11事件及其后果等方面,对美国穆斯林社团的现状和未来可能的发展道路进行了分析。     

MEDICAL MANAGEMENT OF INFANT INTERSEX: THE JURIDICO‐ETHICAL DILEMMA OF CONTEMPORARY ISLAMIC LEGAL RESPONSE

Technological advances in the field of medicine and health sciences not only manipulate the normal human body and sex but also provide for surgical and hormonal management of hermaphroditism (intersexuality). Consequently, sex assignment surgery has not only become a standard care for babies born with genital abnormalities in the West but even in some Muslim states. On the positive side, it goes a long way in saving children born with abnormal genitalia from numerous legal interdictions of the pre‐sex corrective surgery. Nevertheless, the larger ethical and legal questions that medical management of genital abnormality raises to some extent have not been adequately appreciated by contemporary Muslim responses. This article, therefore, in principle argues against surgical management of intersexuality during early infancy from the Islamic legal perspective.     

The Effect of Non-sentential Context Prosody on Homographs’ Lexical Activation in Persian

This study examines the effect of non-sentential context prosody pattern on lexical activation in Persian. For this purpose a questionnaire including target and non-target words is used. The target words are homographs with two possible stress patterns belonging to different syntactic categories. Participants are asked to read out the words aloud and note the first word that comes to their mind. The results show that by reading the target words, both meanings of the target words are activated in mind and the prosodic pattern of the non-sentential preceding context does not affect the activation of the other stress pattern meaning. This result suggests that the metrical prosodic pattern of non-sentential context is not a strong constraint to determine which meaning of the target word must be activated. The experiment also illustrates that the stress pattern used to read the target words does not necessarily matches the stress pattern of the target word which relates to the written word. These findings confirm Swinney (Verb Learn Verb Behav 18:645–665, 1979) and Elston-Güttler and Friederici’s (J Mem Lang 52(2):256–283, 2005) finding that both meanings of an ambiguous word are accessed at the first stage. This study shows that in lack of semantic context, Persian natives behave homographs as ambiguous words and there is no bias towards preferring one meaning over another.