On the asymptotic distribution of Pearson’s X 2 in cross-validation samples

In categorical data analysis, two-sample cross-validation is used not only for model selection but also to obtain a realistic impression of the overall predictive effectiveness of the model. The latter is of particular importance in the case of highly parametrized models capable of capturing every idiosyncracy of the calibrating sample. We show that for maximum likelihood estimators or other asymptotically efficient estimators Pearson's X ² is not asymptotically chi-square in the two-sample cross-validation framework due to extra variability induced by using different samples for estimation and goodness-of-fit testing. We propose an alternative test statistic, X _xval ², obtained as a modification of X ² which is asymptotically chi-square with C−1 degrees of freedom in cross-validation samples. Stochastically, X _xval ² ≤ X ². Furthermore, the use of X ² instead of X _xval ² with a χ _C −1² reference distribution may provide an unduly poor impression of fit of the model in the cross-validation sample. This paper is dedicated to the memory of Michael V. Levine. Requests for reprints should be sent to Albert Maydeu-Olivares, Faculty of Psychology, University of Barcelona, P. Valle de Hebrón, 171, 0835 Barcelona, Spain.     

Limited Information Goodness-of-fit Testing in Multidimensional Contingency Tables

We introduce a family of goodness-of-fit statistics for testing composite null hypotheses in multidimensional contingency tables. These statistics are quadratic forms in marginal residuals up to order r. They are asymptotically chi-square under the null hypothesis when parameters are estimated using any asymptotically normal consistent estimator. For a widely used item response model, when r is small and multidimensional tables are sparse, the proposed statistics have accurate empirical Type I errors, unlike Pearson's X ². For this model in nonsparse situations, the proposed statistics are also more powerful than X ². In addition, the proposed statistics are asymptotically chi-square when applied to subtables, and can be used for a piecewise goodness-of-fit assessment to determine the source of misfit in poorly fitting models. This research has been supported by the Department of Universities, Research, and Information Society (DURSI) of the Catalan Government, by grant BSO2003-08507 of the Spanish Ministry of Science and Technology, and an NSERC Canada grant. We are grateful to the referees for comments leading to improvements.     

RATIONAL EMOTIVE BEHAVIOR THERAPY AND THE MINDFULNESS BASED STRESS REDUCTION TRAINING OF JON KABAT-ZINN

Important aspects of Kabat-Zinn’s mindfulness-based stress reduction (MBSR) are compared, point-by-point, with Albert Ellis’ Rational Emotive Behavior Therapy (REBT). There are some significant differences, since REBT does not advocate meditation as part of the therapy, and MBSR does not include disputing of irrational beliefs. But the similarities are even more striking, especially in the stress on self-acceptance, and in not judging people overall.     

Rational emotive behavior therapy successes and failures: Eight personal perspectives

Eight experts in Rational Emotive Behavior Therapy (REBT) provided personal examples of their own successes and failures in applying REBT to themselves. The experts actively talked to themselves both rationally and irrationally. Understandably, there were far more shoulds, oughts, musts, and have to’s in the narratives in which the experts described when they failed to use REBT than when they succeeded in using REBT. Rational self-talk was more prevalent in the examples of how REBT was successfully used by the experts. Reprinted from Journal of Counseling & Development, Summer 2001, Volume 79. ACA. Reprinted with permission. No further reproduction authorized without written permission from the American Counseling Association.     

"征兆":意识形态的创伤性内核——齐泽克意识形态理论初论

齐泽克从马克思对“商品拜物教”的分析出发,揭露了意识形态的不完整性。在他看来,“征兆”作为沟通前符号界和现实界的桥梁,在意识形态建构起来的看似完整的象征秩序中打开了缺口,挑战了意识形态的“真实”,因此“征兆”是意识形态的“崩溃点”。传统资本主义社会的“劳动力的自由”和“等价交换”、当代资本主义社会的“民主主义”和“排犹主义”就是这种征兆。     

3～5岁儿童表面与结构相似性类比推理的实验研究

采用经典类比推理问题对3~5岁儿童表面相似性与结构相似性类比推理能力进行了实验研究。结果发现:(1)表面相似性与结构相似性对儿童解决类比问题的影响不同。一般来说,前者更有利于3~5岁儿童类比问题的解决;(2)儿童解决表面相似性与结构相似性类比问题的能力随年龄增长而发展,但发展趋势不同。在表面相似性问题方面,4岁以前发展较慢,而4岁以后的发展较快;在结构相似性问题方面,4岁以前发展较快,而4岁以后的发展较慢。4岁是儿童解决类比推理问题能力的转折点;(3)在本实验条件下,工作记忆负荷对儿童解决表面相似性类比问题与结构相似性类比问题的影响不显著;(4)类比映射关系提示能促进儿童解决两类类比问题,但对不同年龄儿童的作用是非线性的。     

中小学生数学知识观的调查研究

本研究采用12道假设性情境题目和包含数学涉及运算、思考、实用性三个维度的数学认识问卷,选取90名六年级小学生和106名初二学生作为被试,探讨中小学生的数学知识观。结果表明:1)中小学生数学知识观形成及发展与学校数学课程内容紧密相关。2)中小学生数学知识观存在差异,主要表现在初二学生对假设性情境的认同程度显著地高于六年级学生;在数学认识问卷的数学实用性维度上,六年级学生的肯定程度显著地高于初二学生。3)从总体上看,学生的学业水平与数学知识观的关系不大。     

农村流动人口的流动模式与其STD/HIV高危性行为的关系

本研究旨在探讨从农村到城市的流动人口的流动模式和高危性行为状况,分析流动模式与他们高危性行为的关系。根据流动人口的职业分布采取配额的方式从北京和南京两座城市共选取了有效被试4301名,其中北京2201名。评估了他们的流动性包括流动时间、流动城市和与性病/艾滋病(STD/HIV)有关的高危性行为包括发生性行为的时间、多个性伙伴和参与商业性行为状况、使用安全套状况。分析结果发现:(1)流动人口的流动性大,平均为0.77,男性、未婚的、年龄小于20岁的流动性比女性、已婚的和年龄大于20岁的显著大;(2)流动人口存在一定比例的高危性行为,男性和未婚的高危性行为显著多于女性和已婚的,尤其是安全套使用率低;(3)不同流动时间、流动城市和流动性的人在高危性行为有些显著差异,总的来说,流动时间越长、流动城市越多、流动性越大的人存在着更多的高危性行为。