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811.
Gerhard H. Fischer 《Psychometrika》1995,60(4):459-487
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. 相似文献
812.
Event-related potentials were used to study how parsing of German relative clauses is influenced by semantic information. Subjects read well-formed sentences containing either a subject or an object relative clause and answered questions concerning the thematic roles expressed in those sentences. Half of the sentences contained past participles that on grounds of semantic plausibility biased either a subject or an object relative reading; the other half contained past participles that provided no semantic information favoring either reading. The past participle elicited an N400 component, larger in amplitude for neutral than for semantically biased verbs, but this occurred only in the case of subject relative clauses. More specific effects were obtained only for a subgroup of subjects, when these were grouped into fast and slow comprehenders on the basis of their questionanswering reaction times. Fast comprehenders showed larger N400 amplitudes for neutral than for semantically biased past participles in general and larger N400s for the latter when there was a bias for an object relative reading as opposed to a subject relative reading. Syntactic ambiguity resolution, indicated by an auxiliary in sentence final position, was associated in this subgroup with a positive component (P345), larger in amplitude for auxiliaries indicating an object relative reading than for those indicating a subject relative reading. The latter component was independent of semantically biasing information given by a preceding past participle. Implications of these findings for models of language comprehension are considered. 相似文献
813.
John D. Teasdale Barbara H. Dritschel Melanie J. Taylor Linda Proctor Charlotte A. Lloyd Ian Nimmo-Smith Alan D. Baddeley 《Memory & cognition》1995,23(5):551-559
Stimulus-independent thoughts (SITs) are streams of thoughts and images unrelated to immediate sensory input. Four experiments examined the contribution of aspects of working memory to production of SITs. In Experiments 1 and 2, interventions that were targeted on, respectively, phonological and visuospatial components of working memory both interfered with production of SITs, but there was evidence that these tasks also made demands on central executive resources. Experiments 3 and 4 specifically examined the hypothesis that production of SITs and control of nonproceduralized tasks both depend on central executive resources, and so should show mutual interference. In Experiment 3, prior practice on pursuit rotor and memory tasks reduced the interference with SITs from concurrent task performance. In Experiment 4, randomness within a task involving random-number generation was less when SITs were being produced concurrently than it was when they were not. The results suggest that production of SITs depends on central executive resources. 相似文献
814.
There has been a paucity of research that has investigated whether skilled performers of a complex sports skill can readily change their technique. This study was designed to investigate whether swimmers skilled in the conventional breaststroke technique could adjust readily to the wave action technique. Nine masters swimmers with well established and stable movement patterns for the conventional technique were coached in the wave action breaststroke technique. The swimmers were videotaped from the side during maximum speed trials of the conventional breaststroke technique before coaching and the wave action technique after ten 45-minute coaching sessions. The amplitude and phase of the waveforms comprising the vertical displacements of the body parts were determined by Fourier analysis. In response to the coaching, the amplitude of the fundamental frequency of the vertex of the head, shoulders, hips, and knees increased significantly (p < 0.01). The percentage of power contained in the fundamental frequency of the shoulder and hip vertical displacements also increased significantly (p < 0.01). All subjects changed the relative phase of the fundamental frequencies of the vertex, shoulder, and hip vertical displacements. It was concluded that in this complex skill, major changes to the low frequency waveforms comprising the motion were achieved readily. 相似文献
815.
ABSTRACT Biomedical experimentation on animals is justified, researchers say, because of its enormous benefits to human beings. Sure, animals suffer and die, but that is morally insignificant since the benefits of research incalculably outweigh the evils. Although this utilitarian claim appears straightforward and relatively uncontroversial, it is neither straightforward nor uncontroversial. This defence of animal experimentation is likely to succeed only by rejecting three widely held moral presumptions. We identify these assumptions and explain their relevance to the justification of animal experimentation. We argue that, even if non-human animals have considerably less moral worth than humans, experimentation is justified only if the benefits are overwhelming. By building on and expanding on arguments offered in earlier papers, we show that researchers cannot substantiate their claims on behalf of animal research. We conclude that there is currently no acceptable utilitarian defence of animal experimentation. Moreover, it is unlikely that there could be one. Since most apologists of animal experimentation rely on utilitarian justifications of their practice, it appears that biomedical experimentation on animals is not morally justified . 相似文献
816.
817.
Although there is considerable empirical support for the existence of social stereotypes about different types of mothers, the content of those stereotypes is less clear. The purpose of this study was to identify the content of stereotypes related to different types of mothers. Stereotyped attributes of married mothers, stepmothers, divorced mothers, and never married mothers were generated by several samples and combined into one list. A subsequent sample was asked to indicate the percentage of each type of mother possessing each characteristic. The content of mother stereotypes was examined, and the results discussed in light of effects on social interactions, the self-image of women, and future attempts to assess family-related stereotypes. 相似文献
818.
Size and orientation of objects in explicit and implicit memory: A reversal of the dissociation between perceptual similarity and type of test 总被引:3,自引:0,他引:3
H. D. Zimmer 《Psychological research》1995,57(3-4):260-273
Memory of size and orientation of objects was tested in explicit and implicit memory tests. Explicit memory was tested by object recognition and by recognition of the congruency of the changed sensory features. Implicit memory was tested by size assessment (Exps. 1 and 2), orientation judgement (Exps. 4 and 5), picture-fragment naming (Exp. 6), and classification (Exps. 3 and 7). Memory of sensory features was investigated by the comparison of performances of test-congruent with test-incongruent stimuli (i.e., same size or orientation vs. different size or orientation). The main result was a dissociation between these two tasks pertaining to the influence of sensory congruency on performance. However, it was in opposition to the usual relationship between the type of test and the perceptual similarity from study to test. In this study explicit, but not implicit, memory depended on sensory congruency. In the explicit tests performances were better when the stimuli were congruent than when they were incongruent. In the implicit test this variation had no influence. To get a repetition effect, it was important only that the object was repeated, and the size of this effect did not depend on sensory congruency. However, a change in another sensory feature — distortions of shape — strongly influenced the size of the repetition effect in the implicit test. Neither transfer-appropriate processing nor a system approach can easily explain this pattern of results. A multi-level, multi-token model is proposed to account for the different effects of sensory features in explicit and implicit memory. 相似文献
819.
MATERNITY LEAVE AND WOMEN'S MENTAL HEALTH 总被引:4,自引:0,他引:4
Janet Shibley Hyde Marjorie H. Klein Marilyn J. Essex Roseanne Clark 《Psychology of women quarterly》1995,19(2):257-285
The Wisconsin Maternity Leave and Health Study addresses an important policy issue, parental leave, by investigating the work status, maternity leave, and mental health of 570 women. In the longitudinal design, the women, all of whom were living with a husband or partner, were interviewed during the fifth month of pregnancy, 1 month postpartum, and 4 months postpartum. At 4 months postpartum, full-time workers, part-time workers, and homemakers did not differ in depression or anger, but full-time workers showed elevated anxiety compared with the other two groups. In multiple regression analyses, length of leave interacted significantly with marital concerns when predicting depression; women who took a short leave (6 weeks or less) and were high on marital concerns had the highest depression scores. Short maternity leave can be conceptualized as a risk factor that, when combined with other risk factors such as marital concerns, places women at greater risk for depression. 相似文献
820.
Robert H. Pate 《Journal of counseling and development : JCD》1995,74(2):181-184
The guest editorial and featured articles have established the fact of counseling specialties and also that counselors have no clear or consistent scheme to recognize professional specialization. If counselors expect external recognition of and respect for their credentials, the credentials first must be recognized and understood by counselors. The experiences of other professions suggest strategies, but counselors must determine their own way of recognizing specialties without denying counselors' common identity. The profession and practice of counseling will be strengthened if all counselors have a minimum foundation of counseling knowledge and competencies and build accepted specializations on that foundation. The counseling profession must distinguish among work settings, professional interests, and specializations as a prerequisite to a coherent scheme of recognizing specialties. 相似文献