多级属性Q矩阵的验证与估计

多级属性是将诊断测验中传统的二值(即两种水平, 通常定义为0和1)属性定义为多值(多个水平可以为0, 1, …), 它不但可以描述学生对于知识属性是否掌握, 而且可以描述学生在属性上的掌握程度, 这样使得诊断测验能提供给被试更丰富的知识掌握详情。本文将适用于二级属性Q矩阵的统计量(S统计量)拓展到多级属性下的Q矩阵验证和估计, 在两种常见的条件下, 设计了两种估计算法：联合估计算法和在线估计算法。模拟实验结果表明：联合估计算法适用于对专家界定的初始Q矩阵进行验证, 当初始Q矩阵中包含较少的错误时, 通过联合估计算法有很大可能恢复正确的Q矩阵; 在线估计算法适用于对“新项目”进行属性向量和项目参数的在线标定, 基于一定数量的“基础项目”, 在线估计算法对于新项目的估计也能达到较满意的成功率。实证数据分析则进一步展示了该方法的使用。     

Embedding Logics into Product Logic

We construct a faithful interpretation of ukasiewicz's logic in product logic (both propositional and predicate). Using known facts it follows that the product predicate logic is not recursively axiomatizable.We prove a completeness theorem for product logic extended by a unary connective of Baaz [1]. We show that Gödel's logic is a sublogic of this extended product logic.We also prove NP-completeness of the set of propositional formulas satisfiable in product logic (resp. in Gödel's logic).     

A Draft for Unifying Controversies in Philosophy of Science

The basic (negative and positive) methodological maxims of three currents of philosophy of science (logical empiricism, falsificationism, and postpositivism) are formulated. Many of these maxims (stratagems) are controversial, e.g., the stance about the nonsense of metaphysics, and that of its indispensability. The restricted validity of these maxims allows for their unification. Within the framework of most of them there may be a relationship of (synchronic, or diachronic) subordination of the contradicting desiderata. In this vein ten stratagems are formulated. This revised version was published online in August 2006 with corrections to the Cover Date.     

Situation Awareness: Its proficiency amongst older and younger drivers,and its usefulness for perceiving hazards

The two studies reported here sought to measure and compare the Situation Awareness (SA) of younger and older driver groups whilst driving (Study 1), and watching video footage of actual car journeys (Study 2). In both studies this was achieved by recording a participant’s commentary on what s/he felt was of relevance to the driving task. The narratives produced were analysed by computer software that could abstract main concepts and calculate scores indicative of Situation Awareness. In Study 2, these scores were related to others for hazard perception proficiency (also derived from participant commentaries). It was found that the older drivers matched and often exceeded the younger drivers when their SA scores were compared individually, but not when assessed as a group. However, the younger drivers out-performed their older counterparts in hazard perception ability, and this was shown to be related to their Situation Awareness score. When the results from participants who undertook both studies were compared, it was found that Situation Awareness performance was significantly higher when commenting on video footage (Study 2) than whilst actually driving (Study 1).     

Exploring athletes' perceptions of the relationship between mental toughness and dispositional flow in sport

ObjectivesDespite considerable scholarly attention over the last two decades, little is known about the influence of dispositional attributes on flow in sport. In achievement settings, mental toughness (MT) is a personal capacity supporting the process of high performance. Based on common overlaps with peak performance, confidence, control, concentration, and thriving in demanding situations, the present research aimed to explore the relationship between MT and dispositional flow and elucidate the psychological variables underlying dispositional flow.DesignA mixed method explanatory participant-selection design was adopted, whereby a quantitative approach was used to identify individuals for a qualitative follow-up phase to explore the relationship between MT and dispositional flow.MethodAn intensity sampling strategy was used to identify individuals with higher/lower MT and dispositional flow. Semi-structured interviews were conducted with 16 athletes (M age = 25, SD = 3.24; female n = 10; male n = 6). An inductive content analysis was undertaken to interpret data.ResultsSeven general dimensions describing the psychological attributes related to dispositional flow in athletes with higher and lower MT emerged. Specifically, differences in confidence, perfectionism, goal orientation, coping mechanism selection, locus of control, optimism and concentration were apparent and could account for differences in dispositional flow.ConclusionWhile all athletes experienced flow, there were differences in dispositional flow and the processes involved in entering, maintaining and restoring flow between higher and lower MT subgroups. Findings are discussed in relation to the existing literature, and recommendations for future research into the MT-flow relationship are outlined.     

样例设计及呈现方式对学习代数运算规则的促进

为了考察"解释法"、"解释-标记法"两种样例设计方法及其"分步呈现"方式对六年级小学生学习代数运算规则的促进作用,以六年级小学生为被试,以"完全平方和"和"平方差"代数运算样例为学习材料,进行了3项实验研究。结果表明:(1)采用"解释法"设计"完全平方和"和"平方差"的代数运算样例,明显提高了代数运算规则的样例学习效果。(2)在"解释法"设计的样例上添加"运算标记"要运用适当,如果运用不当,特别是"运算标记"过多时,容易增加样例学习的认知负荷,从而降低标记的使用效果。(3)对于运算步骤和"运算标记"过多的样例,采用被试自主控制的"分步呈现"运算步骤的样例学习方式,其学习效果显著优于整体呈现样例的学习效果。     

论医学哲学的特征

医学哲学也称为医学辩证法,是在总结医学科学成就的基础上,通过对医学理论和实践中一般、普遍、共性问题的研究,揭示医学认识主体思维活动普遍规律的科学：是人们认识和处理健康和疾病问题的一般方法论。无论是与医学还是与哲学相比。医学哲学都有着显著的区别,运用对比分析的方法。对医学哲学的研究对象、理论体系特别是思维方式等不同方面的特征,进行理论探讨。     

An evaluation of multi‐criteria methods in integrated assessment of climate policy

Those who conduct integrated assessments (IAs) are aware of the need to explicitly consider multiple criteria and uncertainties when evaluating policies for preventing global warming. MCDM methods are potentially useful for understanding tradeoffs and evaluating risks associated with climate policy alternatives. A difficulty facing potential MCDM users is the wide range of different techniques that have been proposed, each with distinct advantages. Methods differ in terms of validity, ease of use, and appropriateness to the problem. Alternative methods also can yield strikingly different rankings of alternatives. A workshop was held in which climate change experts and policy makers evaluated the usefulness of MCDM for IA. Participants applied several methods in the context of a hypothetical greenhouse gas policy decision. Methods compared include value and utility functions, goal programming, ELECTRE, fuzzy sets, stochastic dominance, min max regret, and several weight selection methods. Ranges, rather than point estimates, were provided for some questions to incorporate imprecision regarding weights. Additionally, several visualization methods for both deterministic and uncertain cases were used and evaluated. Analysis of method results and participant feedback through questionnaires and discussion provide the basis for conclusions regarding the use of MCDM methods for climate change policy and IA analyses. Hypotheses are examined concerning predictive and convergent validity of methods, existence of splitting bias among experts, perceived ability of methods to aid decision‐making, and whether expressing imprecision can change ranking results. Because participants gained from viewing a problem from several perspectives and results from different methods often significantly differed, it appears worthwhile to apply several MCDM methods to increase user confidence and insight. The participants themselves recommended such multimethod approaches for policymaking. Yet they preferred the freedom of unaided decision‐making most of all, challenging the MCDM community to create transparent methods that permit maximum user control. Copyright © 2002 John Wiley & Sons, Ltd.