Hard‐to‐Solve Bimatrix Games

The Lemke–Howson algorithm is the classical method for finding one Nash equilibrium of a bimatrix game. This paper presents a class of square bimatrix games for which this algorithm takes, even in the best case, an exponential number of steps in the dimension d of the game. Using polytope theory, the games are constructed using pairs of dual cyclic polytopes with 2d suitably labeled facets in d‐space. The construction is extended to nonsquare games where, in addition to exponentially long Lemke–Howson computations, finding an equilibrium by support enumeration takes on average exponential time.     

Using latent class analysis to detect behavioral patterns in systems of observational variables

Behavioral observation is widely used for data gathering in evaluation research. Yet it leaves the investigator with unique problems. Usually, multiple observations result in a hierarchical data set, where numerous data records exist for each subject. Researchers face data reduction problems at least at two levels. First, there is the well-known and often-addressed problem of reducing the number of variables in a data set with only one information record per individual. Second, there is the problem of summarizing data at the individual subject level. The easiest way to perform this latter type of aggregation involves using univariate summary measures as probabilities of “using” an item, means, or standard deviations for each item per subject. Other standard procedures include first order interactions between pairs of items. However, use of pair-wise interactions is restricted because of variable dependence within each subject (this Affects e.g. factor analysis), or because of the relatively high number of single observations (this Affects e.g., cluster analysis). In this paper we propose employing Latent Class Analysis (LCA) to reduce the amount of information in observational data sets. In a first step, LCA allows one to specify intraindividual behavior patterns. In a second step, LCA allows one to derive meaningful summary scores for each individual. The two steps are illustrated using data that describe peer play competence in Swedish toddlers.     

Schulverweigerung

The aim of this article is to describe the extent of truancy in Cologne and to identify the relevant predictors. Hypotheses are deduced from classical deviance theories (control theory, amomy theory, theory of urban subcultures) and tested empirically. Our analysis is based on a survey of pupils in Cologne from grade 8 to 10 which was conducted in 1999 by the Max Planck Institute for Foreign and International Criminal Law in Freiburg. Our results show that 7.9 percent of all respondends can be defined as truants. Boys play truant more than girls, and the higher the age, the more pupils bunk off school. More important than gender and age is the type of secondary school. We find the highest amount of truants at Hauptschulen and Sonderschulen. It is shown that truancy is a multidimensional phenomenon that cannot be explained by just one single theory.     

PROPERLY RESCALED COMPONENTS OF SMOOTH TESTS OF FIT ARE DIAGNOSTIC

The paper illustrates a typical pitfall associated with a conventional interpretation of components of smooth tests of fit, for example the first nonzero components of the smooth tests for Poissonity, exponentiality, normality and the geometric distribution. In order to achieve a directed diagnosis concerning the kind of departure from a hypothesised model, an appropriate rescaling of components is necessary.     

“学前教育”、”幼儿教育”与”早期教育”等基本概念内涵界定及应用——“全国高校学前教师微信群”2017新年网络主题研讨会笔谈综述

为了切实推进学前教育学科体系建设与科研工作,陕西学前师范学院学报编辑部在“全国高校学前教师微信群”发起了2017新年网络主题研讨会笔谈活动,从儿童发展、学制阶段、国际分类、实践经验、学科术语、跨国译介、约定俗成与人才培养等多个视角对“学前教育”、”幼儿教育”与”早期教育”等基本概念的内涵界定问题进行了探讨,指出我国学前教育学科体系建设不仅应尽早推动研究重心从3-6岁“幼儿教育”领域向0-3岁“早期教育”领域的内部前移,而且要尽早推动研究纵深从0-6岁“学前教育”领域向0-12岁“儿童教育”领域的外部拓展。