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191.
This paper concerns items that consist of several item steps to be responded to sequentially. The item scoreX is defined as the number of correct responses until the first failure. Samejima's graded response model states that each steph=1,...,m is characterized by a parameterb
h
, and, for a subject with ability, Pr(Xh; )=F(–b
h
). Tutz's general sequential model associates with each step a parameterdh, and it states that Pr(Xh;)=
r
=1h
G(–d
r
). Tutz's (1991, 1997) conjectures that the models are equivalent if and only ifF(x)=G(x) is an extreme value distribution. This paper presents a proof for this conjecture. 相似文献
192.
Cognitive processing in literate and illiterate subjects: a review of some recent behavioral and functional neuroimaging data 总被引:4,自引:0,他引:4
The study of illiterate subjects, which for specific socio-cultural reasons did not have the opportunity to acquire basic reading and writing skills, represents one approach to study the interaction between neurobiological and cultural factors in cognitive development and the functional organization of the human brain. In addition the naturally occurring illiteracy may serve as a model for studying the influence of alphabetic orthography on auditory-verbal language. In this paper we have reviewed some recent behavioral and functional neuroimaging data indicating that learning an alphabetic written language modulates the auditory-verbal language system in a non-trivial way and provided support for the hypothesis that the functional architecture of the brain is modulated by literacy. We have also indicated that the effects of literacy and formal schooling is not limited to language related skills but appears to affect also other cognitive domains. In particular, we indicate that formal schooling influences 2D but not 3D visual naming skills. We have also pointed to the importance of using ecologically relevant tasks when comparing literate and illiterate subjects. We also demonstrate the applicability of a network approach in elucidating differences in the functional organization of the brain between groups. The strength of such an approach is the ability to study patterns of interactions between functionally specialized brain regions and the possibility to compare such patterns of brain interactions between groups or functional states. This complements the more commonly used activation approach to functional neuroimaging data, which characterize functionally specialized regions, and provides important data characterizing the functional interactions between these regions. 相似文献
193.
194.
初中词汇理解能力量表的编制 总被引:4,自引:2,他引:2
应用项目反应理论为初中各年级编制了词汇理解能力的测验,其中包含了143个多项选择的词汇项目,经过反复预测和大规模的正式测试,证关了这三个测验的量表拟全于2PL模型,项目特征曲线拟合度良好的项目占全体项目数90%以上,能力的一维性也得以确认,经等值化后,各年级的区分度均值分别为0.61(初一),0.59(初二),0.55(初三)难度均值分别为-1.61,-1.30,-0.56。 相似文献
195.
196.
Jutta Schickore 《Journal for General Philosophy of Science》1999,30(2):273-287
Vision, Visibility, and Empirical Research. In general, natural scientists use the concept of observation in a liberal way:
they talk of observing electrons, DNA, or distant quasars. Several philosophers of science have recently argued for a similar
use of the concept of observation: they have claimed that the important aspects of scientific research can only be properly
reconstructed in accordance with how this term is actually used in science. With reference to an example from astronomy, I
point out that the proposed generalisation of the concept of observation leads to undesirable consequences. I argue that a
differentiated conceptual framework is required in order to give an adequate account of the varieties of scientific experience.
Thus, the appropriate starting point for distinguishing these various scientific research practices should not be the generalised
scientific conception of observation, but instead distinctly different uses of the term observation drawn from ordinary language.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
197.
Although there has been a proliferation of models of supervision in the marriage and family therapy literature recently, most tend to focus on methods rather than on the process of supervision. The model presented here is grounded in developmental concepts and focuses on student learning through a dialectical process of cognitive and emotional growth and incorporates three stages: 1) developing relationships; 2) breaking impasses, and 3) orchestrating changes. Students discover that supervision becomes isomorphic with relationship issues that arise in their therapy sessions. Dialectical in nature in that each stage is characterized by the resolution of contradictory emotions, the supervision process helps supervisees experience emotional shifts in their interactions with others, referred to as emotional restructuring. 相似文献
198.
Ken Cheng 《Animal cognition》1999,2(2):73-78
Honeybees were trained to find sugar water in the middle of an array of two landmarks of different colours. Unrewarded tests
compared searching on the training array with searching on rotated arrays. On rotated tests, a system using the angles between
landmarks would continue to search in the middle. A system using vectors to individual elements would search at locations
outside the rotated array at which the distances and compass directions to a subset of landmarks matched. Results indicated
that bees used both elements and interlandmark angles, but they relied most on one favourite landmark element. Results support
the template model of landmark use in honeybees, with the minor parametric modification that weights given to different elements
may be unequal.
Received:6 July 1998 / Accepted after revision:7 December 1998 相似文献
199.
汉字词识别过程的形,音,义编码作用的研究 总被引:7,自引:0,他引:7
本文通过两个实验,采用汉字词形、音、义特征匹配任务,探讨了影响汉字词的形、音、义编码与提取方式的有关因素。实验一发现在速示条件下,对汉字词再认的成绩并不受字词的使用度的影响,反应时无明显变化,而主要受编码加工的深度影响。在形、音、义特征加工中,对音码的加工时间最长,再认的正确率最低;义码的加工时间较短,再认正确率最高;形码的反应时及再认成绩介于音码与义码之间。实验二在非速示条件下也获得了相同的结果。研究结果表明,在汉字词的形、音、义特征中,存在着编码加工深度的差异。 相似文献
200.
In this paper, the constrained maximum likelihood estimation of a two-level covariance structure model with unbalanced designs is considered. The two-level model is reformulated as a single-level model by treating the group level latent random vectors as hypothetical missing-data. Then, the popular EM algorithm is extended to obtain the constrained maximum likelihood estimates. For general nonlinear constraints, the multiplier method is used at theM-step to find the constrained minimum of the conditional expectation. An accelerated EM gradient procedure is derived to handle linear constraints. The empirical performance of the proposed EM type algorithms is illustrated by some artifical and real examples.This research was supported by a Hong Kong UCG Earmarked Grant, CUHK 4026/97H. We are greatly indebted to D.E. Morisky and J.A. Stein for the use of their AIDS data in our example. We also thank the Editor, two anonymous reviewers, W.Y. Poon and H.T. Zhu for constructive suggestions and comments in improving the paper. The assistance of Michael K.H. Leung and Esther L.S. Tam is gratefully acknowledged. 相似文献