基于因果关系的教育研究方法思考

探索、检验因果关系是教育科学研究的重要目标之一,相关分析、回归分析、路径分析等常用统计方法存在许多不足。结构方程模型是针对这些不足提出来的,从统计思路上,它具有优点,但还不够完善,应引起我国教育学界的注意。     

A Tiered Framework for Risk‐Relevant Characterization and Ranking of Chemical Exposures: Applications to the National Children's Study (NCS)

A challenge for large‐scale environmental health investigations such as the National Children's Study (NCS), is characterizing exposures to multiple, co‐occurring chemical agents with varying spatiotemporal concentrations and consequences modulated by biochemical, physiological, behavioral, socioeconomic, and environmental factors. Such investigations can benefit from systematic retrieval, analysis, and integration of diverse extant information on both contaminant patterns and exposure‐relevant factors. This requires development, evaluation, and deployment of informatics methods that support flexible access and analysis of multiattribute data across multiple spatiotemporal scales. A new “Tiered Exposure Ranking” (TiER) framework, developed to support various aspects of risk‐relevant exposure characterization, is described here, with examples demonstrating its application to the NCS. TiER utilizes advances in informatics computational methods, extant database content and availability, and integrative environmental/exposure/biological modeling to support both “discovery‐driven” and “hypothesis‐driven” analyses. “Tier 1” applications focus on “exposomic” pattern recognition for extracting information from multidimensional data sets, whereas second and higher tier applications utilize mechanistic models to develop risk‐relevant exposure metrics for populations and individuals. In this article, “tier 1” applications of TiER explore identification of potentially causative associations among risk factors, for prioritizing further studies, by considering publicly available demographic/socioeconomic, behavioral, and environmental data in relation to two health endpoints (preterm birth and low birth weight). A “tier 2” application develops estimates of pollutant mixture inhalation exposure indices for NCS counties, formulated to support risk characterization for these endpoints. Applications of TiER demonstrate the feasibility of developing risk‐relevant exposure characterizations for pollutants using extant environmental and demographic/socioeconomic data.     

大数据背景下网络调查样本的建模推断问题研究——以广义Boosted模型的倾向得分推断为例

随着大数据和网络的不断发展,网络调查越来越广泛,大部分网络调查样本属于非概率样本,难以采用传统的抽样推断理论进行推断,如何解决网络调查样本的推断问题是大数据背景下网络调查发展的迫切需求。本文首次从建模的角度提出了解决该问题的基本思路：一是入样概率的建模推断,可以考虑构建基于机器学习与变量选择的倾向得分模型来估计入样概率推断总体;二是目标变量的建模推断,可以考虑直接对目标变量建立参数、非参数或半参数超总体模型进行估计;三是入样概率与目标变量的双重建模推断,可以考虑进行倾向得分模型与超总体模型的加权估计与混合推断。最后,以基于广义Boosted模型的入样概率建模推断为例演示了具体解决方法。     

Estimating consumer acceptance limits

A methodology is developed for estimating consumer acceptance limits on a sensory attribute of a manufactured product. In concept these limits are analogous to engineering tolerances. The method is based on a generalization of Stevens' Power Law. This generalized law is expressed as a nonlinear statistical model. Instead of restricting the analysis to this particular case, a strategy is discussed for evaluating nonlinear models in general since scientific models are frequently of nonlinear form. The strategy focuses on understanding the geometrical contrasts between linear and nonlinear model estimation and assessing the bias in estimation and the departures from a Gaussian sampling distribution. Computer simulation is employed to examine the behavior of nonlinear least squares estimation. In addition to the usual Gaussian assumption, a bootstrap sample reuse procedure and a general triangular distribution are introduced for evaluating the effects of a non-Gaussian or asymmetrical error structure. Recommendations are given for further model analysis based on the simulation results. In the case of a model for which estimation bias is not a serious issue, estimating functions of the model are considered. Application of these functions to the generalization of Stevens’ Power Law leads to a means for defining and estimating consumer acceptance limits, The statistical form of the law and the model evaluation strategy are applied to consumer research data. Estimation of consumer acceptance limits is illustrated and discussed.     

The Consistent System

The Consistent System (CS) is an interactive computer system for researchers in the behavioral and policy sciences and in fields with similar requirements for data management and statistical analysis. The researcher is not expected to be a programmer. The system offers a wide range of facilities and permits the user to combine them in novel ways. In particular, tools for statistical analysis may be used in combination with a powerful relational subsystem for data base management. This paper gives an overview of the objectives, capabilities, status, and availability of the system.     

The Impact of Competitive Strategy and Supply Chain Strategy on Business Performance: The Role of Environmental Uncertainty*

This article investigates the relationships among competitive strategy, supply chain strategy, and business performance while examining the moderating effect of environmental uncertainty. A total of 604 questionnaires were collected from three cities in China, and the statistical results show significant moderating effects of external environment on the relationships among competitive strategy, supply chain strategy, and business performance. Firms that primarily focus on a differentiation strategy emphasize an agile supply chain strategy. Cost leaders are inclined to implement both lean and agile supply chain strategies, but their emphasis on agile strategy is significantly greater in a volatile environment than in a stable environment. The choice of supply chain strategy does not appear to be an “either‐or” decision and firms could adopt either a lean or an agile strategy, or both, depending on the environment. This article provides significant managerial implications for supply chain practitioners to co‐align supply chain strategy and competitive strategy with the environment to improve performance.     

北京郊区农民城镇化意愿影响因素的实证分析

城镇化是一项系统工程,涉及农民意愿,内容涵盖农民城镇生活、农村迁建、土地流转和就业意愿等。农民意愿受个人、家庭和制度等因素的影响,因区域的差异而迥异。文章以北京郊区户籍农民调查数据为基础,运用计划行为(TPB)理论构建结构方程模型(SEM)分析其影响因素。结果证明,运用计划行为理论分析意愿的影响因素是适用的,农民的城镇化行为态度已经处于追求经济理性和价值理性阶段,感知行为控制中的非经济理性、迁居成本和个人特征对意愿有较强影响,农民在做决策时会更多参考亲戚、家人和邻里的意见。     

Approximating probability density functions in hybrid Bayesian networks with mixtures of truncated exponentials

Mixtures of truncated exponentials (MTE) potentials are an alternative to discretization and Monte Carlo methods for solving hybrid Bayesian networks. Any probability density function (PDF) can be approximated by an MTE potential, which can always be marginalized in closed form. This allows propagation to be done exactly using the Shenoy-Shafer architecture for computing marginals, with no restrictions on the construction of a join tree. This paper presents MTE potentials that approximate standard PDF’s and applications of these potentials for solving inference problems in hybrid Bayesian networks. These approximations will extend the types of inference problems that can be modelled with Bayesian networks, as demonstrated using three examples.     

Psychic distance, psychic distance paradox and behavioral economics: Modeling MNC entry behavior in foreign markets

Assuming that MNCs face a much more complex environment that local enterprizes, the paper begins by discussing what economist Beckerman called psychic distance. After a historical discussion of this concept, I also discuss what O’Gardy and Lane called psychic distance paradox. Then, I argue that these two concepts have a great deal of relevance beyond their original intent of international trade-they are also relevant to FDI and all other formas of international production and exchange. Next, I argue, as I have done in several previous papers, that behavioral economics has a great deal of relevance to FDI and international productive activity; I also argue that behavioral economics can be utilized to describe the concepts of psychic distance and psychic distance paradox. Then, I develop a behavioral economics-based model that can explain the concepts of psychic distance and psychic distance paradox, and their relevance to the modes of entry of MNCs in international markets. In doing so, I argue that FDI and MNC behavior in general need not be explained outside of economics, since, in contrast to neo-classical economics, behavioral economics is capable of capturing the complexities of global markets.     

North-South relations: Alternative policy simulations for the world economy in the 1980s

This article makes projections of the world economy in the North-South context for the period 1981–1990 using a latest global version of a macroeconomic model named FUGI-GNEM type IV 011–62. The model classifies the world into 62 countries/regions, where the North-South interdependence is incorporated into an integral part of the world economy through international economic linkages. Based on alternative simulations, the author presents future images of the North-South interdependent world economy through changes in economic growth rates, employment, wages, prices, money supply, interest rates, public finance, trade, capital movement, international balance of payments, foreign exchange rates, etc., in each country or region. The model forecasts that the real economic growth of the developing countries as a whole in the 1980s will likely be around 4%–7% annual rate according to alternative policy scenarios.