3~5岁儿童理解和使用空间表征的特点

以96名3~5儿童为被试,采用自编的儿童空间表征实验任务,在语言表征、模型表征和图画表征三种空间表征形式上,考察了儿童理解和使用空间表征的发展特点。结果表明:(1)总体上,3~5岁儿童理解空间表征的发展水平均显著高于使用空间表征的发展水平。(2)3~5岁儿童理解和使用空间表征的发展表现出显著的年龄效应。(3)从不同的空间表证形式来看,3岁儿童理解语言表征的能力与理解模型表征的能力之间差异显著,4岁儿童使用语言表征的能力与使用模型表征的能力之间的差异、使用语言表征的能力与使用图画表征的能力之间的差异、以及使用模型表征的能力与使用图画表征的能力之间的差异都显著,其余形式的空间表征理解之间的差异或空间表征使用之间的差异在各年龄段中均不显著。     

吉林省医务人员吸烟现况及知识态度分析

为了更好地了解吉林省医务人员的吸烟状况,为进一步开展控烟工作提供科学依据,对吉林省50家医疗机构的3787名医务人员进行问卷调查,调查结果显示,男性医务人员吸烟率较高；医务人员对烟草危害认识不全面,控烟意识较为薄弱.应加强对医务人员烟害知识等方面的培训,以改变其吸烟行为、提高控烟责任意识.     

国内外农村医疗保障的政府规制比较分析

运用政府规制理论，从政府规制机构、政府规制标准和对筹资的规制三个方面对国内外农村医疗保障中的政府规制进行比较分析，从而启发我们要精简规制机构，提高规制效率；完善规制标准，提高规制效力；用法律来规制各级政府对医疗保障补助资金的转移支付。     

On scaling models applied to data from several groups

Statistical methods are presented to facilitate a more complete analysis of results obtained when a scaling model is applied to data from two or more groups. These methods can be used to (a) compare the corresponding estimated latent distributions obtained using the scaling model applied to the different groups, (b) compare the corresponding estimated item reliabilities (or item response error rates) for the different groups, and (c) test whether the scaling model applied to the several groups can be replaced by a more parsimonious scaling model that includes various homogeneity constraints (i.e., constraints that describe which parameters in the model are the same for the several groups). Various kinds of scaling models are considered here in the multiple-group context.Support for this research was provided in part by the National Science Foundation, to Clogg by Grant No. SES-7823759 and to Goodman by Grant No. SES-8303838. Clogg and Goodman were Fellows at the Center for Advanced Study in the Behavioral Sciences when part of the research was done, with financial support provided in part by National Science Foundation grant BNS-8011494 to the Center. The authors are indebted to Mark P. Becker and James W. Shockey for helpful comments.     

Conjunctive item response theory kernels

Conjunctive item response models are introduced such that (a) sufficient statistics for latent traits are not necessarily additive in item scores; (b) items are not necessarily locally independent; and (c) existing compensatory (additive) item response models including the binomial, Rasch, logistic, and general locally independent model are special cases. Simple estimates and hypothesis tests for conjunctive models are introduced and evaluated as well. Conjunctive models are also identified with cognitive models that assume the existence of several individually necessary component processes for a global ability. It is concluded that conjunctive models and methods may show promise for constructing improved tests and uncovering conjunctive cognitive structure. It is also concluded that conjunctive item response theory may help to clarify the relationships between local dependence, multidimensionality, and item response function form.I appreciate the many helpful suggestions that were given by the reviewers and Ivo Molenaar.     

Germ-line gene therapy and the clinical ethos of medical genetics

Although the ability to perform gene therapy in human germ-line cells is still hypothetical, the rate of progress in molecular and cell biology suggests that it will only be a matter of time before reliable clinical techniques will be within reach. Three sets of arguments are commonly advanced against developing those techniques, respectively pointing to the clinical risks, social dangers and better alternatives. In this paper we analyze those arguments from the perspective of the client-centered ethos that traditionally governs practice in medical genetics. This perspective clarifies the merits of these arguments for geneticists, and suggests useful new directions for the professional discussion of germ-line gene therapy. It suggests, for example, that the much discussed prospect of germ-line therapy in human pre-embryos may always be more problematic for medical genetics than adult germ-line interventions, even though the latter faces greater technical difficulties.     

Speech acts and arguments

Speech act theory seems to provide a promising avenue for the analysis of the functional organization of argument. The theory, however, might be taken to suggest that arguments are a homogenous class of speech act with a specifiable illocutionary force and a single set of felicity conditions. This suggestion confuses the analysis of the meaning of speech act verbs with the analysis of the pragmatic structure of actual language use. Suggesting that arguments are conveyed through a homogeneous class of linguistic action overlooks the way in which the context of activity and the form of expression organize the argumentative functions performed in using language. An alternative speech act analysis would treat folk terminology as a heuristic entry point into the development of a technical analysis of the myriad argumentative functions and structures to be found in natural language use. This would lead to a thorough-going pragmatic analysis of the rational and functional design of speech acts in argumentation.     

Sequential sampling designs for the two-parameter item response theory model

In optimal design research, designs are optimized with respect to some statistical criterion under a certain model for the data. The ideas from optimal design research have spread into various fields of research, and recently have been adopted in test theory and applied to item response theory (IRT) models. In this paper a generalized variance criterion is used for sequential sampling in the two-parameter IRT model. Some general principles are offered to enable a researcher to select the best sampling design for the efficient estimation of item parameters.     

Extensions of Rasch's multiplicative poisson model

Consideration will be given to a model developed by Rasch that assumes scores observed on some types of attainment tests can be regarded as realizations of a Poisson process. The parameter of the Poisson distribution is assumed to be a product of two other parameters, one pertaining to the ability of the subject and a second pertaining to the difficulty of the test. Rasch's model is expanded by assuming a prior distribution, with fixed but unknown parameters, for the subject parameters. The test parameters are considered fixed. Secondly, it will be shown how additional between- and within-subjects factors can be incorporated. Methods for testing the fit and estimating the parameters of the model will be discussed, and illustrated by empirical examples.     

樟柳碱所致学习和记忆障碍动物模型的探讨

本实验采用水迷津法、步下法和步入法,用樟柳碱制备学习和记忆障碍的动物模型。结果表明,樟柳碱(10毫克/公斤)可使小鼠引起学习障碍,其表现为通过水迷津全程的时间延长,而且小鼠进入盲路的错误次数明显增多。樟柳碱(10毫克/公斤)可使小鼠引起记忆障碍,在樟柳碱的影响下,小鼠步下平台或步入暗箱的潜伏期明显缩短,并使它们的错误次数增多。本实验结果进一步表明,测定小鼠的记忆障碍,步入法似乎比步下法更为敏感。