知识图式对贝叶斯推理的影响

选取具有概率知识的大学生(专家)和没有概率知识的大学生(新手)为被试,进行贝叶斯推理中的概率估计,探讨知识图式对贝叶斯推理的影响。结果表明,具有概率知识背景的大学生比没有概率知识背景的大学生概率估计的准确性更高,反应时更长,说明知识图式影响概率信息的搜索和判断。     

Comparative evaluation of two superior stopping rules for hierarchical cluster analysis

A split-sample replication stopping rule for hierarchical cluster analysis is compared with the internal criterion previously found superior by Milligan and Cooper (1985) in their comparison of 30 different procedures. The number and extent of overlap of the latent population distributions was systematically varied in the present evaluation of stopping-rule validity. Equal and unequal population base rates were also considered. Both stopping rules correctly identified the actual number of populations when there was essentially no overlap and clusters occupied visually distinct regions of the measurement space. The replication criterion, which is evaluated by clustering of cluster means from preliminary analyses that are accomplished on random partitions of an original data set, was superior as the degree of overlap in population distributions increased. Neither method performed adequately when overlap obliterated visually discernible density nodes.This research was supported in part by NIMH grant 5R01 MH 32457 14.     

因果信息在贝叶斯推理中的作用:问题情境的调节

以大学生为被试,考察因果信息在不同贝叶斯推理问题中的作用。结果表明:(1)问题情境的主效应显著(F(1,122)=16.33,p0.05,η~2=0.120),因果信息的主效应不显著((F(1,122)=1.161,p=0.283,η~2=0.01),但问题类型和因果信息的交互作用显著(F(1,122)=4.757,p0.05,η~2=0.038)。(2)不同类型的问题上因果信息的作用是不同的。具体表现为,在乳癌问题中,增加了因果信息,被试的正确率明显提高(χ~2(1)=6.759,p0.05,V=0.607),而在中彩问题中没有因果信息的推理成绩反而更好(χ~2(1)=1.864,p=0.221,V=0.167)。     

Employees’ perceived institutional importance,organizational norms,and organizational citizenship behavior: Insights from a multilevel assessment of the institutional anomie theory

ABSTRACT

This study contributes to the understanding of organizational citizenship behavior (OCB) and extending the application of institutional anomie theory (IAT). Employing a multilevel moderation framework, this paper explored the influence of employees’ perceived institutional importance to their demonstration of OCB and the moderating impacts of organizational norms on this relationship. Utilizing data of 243 employees from 34 banks in the Philippines, results of the hierarchical linear modeling (HLM) analysis revealed the positive influence of the importance of the economy, family, polity, and religion on employees’ citizenship acts. Furthermore, goal emphasis and socio-emotional support have significant interacting effects on the association between perceived institutional importance and OCB.     

Entailment with Near Surety of Scaled Assertions of High Conditional Probability

An assertion of high conditional probability or, more briefly, an HCP assertion is a statement of the type: The conditional probability of B given A is close to one. The goal of this paper is to construct logics of HCP assertions whose conclusions are highly likely to be correct rather than certain to be correct. Such logics would allow useful conclusions to be drawn when the premises are not strong enough to allow conclusions to be reached with certainty. This goal is achieved by taking Adams" (1966) logic, changing its intended application from conditionals to HCP assertions, and then weakening its criterion for entailment. According to the weakened entailment criterion, called the Criterion of Near Surety and which may be loosely interpreted as a Bayesian criterion, a conclusion is entailed if and only if nearly every model of the premises is a model of the conclusion. The resulting logic, called NSL, is nonmonotonic. Entailment in this logic, although not as strict as entailment in Adams" logic, is more strict than entailment in the propositional logic of material conditionals. Next, NSL was modified by requiring that each HCP assertion be scaled; this means that to each HCP assertion was associated a bound on the deviation from 1 of the conditional probability that is the subject of the assertion. Scaling of HCP assertions is useful for breaking entailment deadlocks. For example, it it is known that the conditional probabilities of C given A and of ¬ C given B are both close to one but the bound on the former"s deviation from 1 is much smaller than the latter"s, then it may be concluded that in all likelihood the conditional probability of C given A B is close to one. The resulting logic, called NSL-S, is also nonmonotonic. Despite great differences in their definitions of entailment, entailment in NSL is equivalent to Lehmann and Magidor"s rational closure and, disregarding minor differences concerning which premise sets are considered consistent, entailment in NSL-S is equivalent to entailment in Goldszmidt and Pearl"s System-Z ⁺. Bacchus, Grove, Halpern, and Koller proposed two methods of developing a predicate calculus based on the Criterion of Near Surety. In their random-structures method, which assumed a prior distribution similar to that of NSL, it appears possible to define an entailment relation equivalent to that of NSL. In their random-worlds method, which assumed a prior distribution dramatically different from that of NSL, it is known that the entailment relation is different from that of NSL.