The nontruncated marginal of a truncated bivariate normal distribution

Inference is considered for the marginal distribution ofX, when (X, Y) has a truncated bivariate normal distribution. TheY variable is truncated, but only theX values are observed. The relationship of this distribution to Azzalini's skew-normal distribution is obtained. Method of moments and maximum likelihood estimation are compared for the three-parameter Azzalini distribution. Samples that are uniformative about the skewness of this distribution may occur, even for largen. Profile likelihood methods are employed to describe the uncertainty involved in parameter estimation. A sample of 87 Otis test scores is shown to be well-described by this model.     

Interpolation and Amalgamation; Pushing the Limits. Part I

Continuing work initiated by Jónsson, Daigneault, Pigozzi and others; Maksimova proved that a normal modal logic (with a single unary modality) has the Craig interpolation property iff the corresponding class of algebras has the superamalgamation property (cf. [Mak 91], [Mak 79]). The aim of this paper is to extend the latter result to a large class of logics. We will prove that the characterization can be extended to all algebraizable logics containing Boolean fragment and having a certain kind of local deduction property. We also extend this characterization of the interpolation property to arbitrary logics under the condition that their algebraic counterparts are discriminator varieties. We also extend Maksimova's result to normal multi-modal logics with arbitrarily many, not necessarily unary modalities, and to not necessarily normal multi-modal logics with modalities of ranks smaller than 2, too.The problem of extending the above characterization result to no n-normal non-unary modal logics remains open.Related issues of universal algebra and of algebraic logic are discussed, too. In particular we investigate the possibility of extending the characterization of interpolability to arbitrary algebraizable logics.     

Obtaining Systematic Teacher Reports of Disruptive Behavior Disorders Utilizing DSM-IV

This study examines the psychometric properties of the Vanderbilt AD/HD Diagnostic Teacher Rating Scale (VADTRS) and provides preliminary normative data from a large, geographically defined population. The VADTRS consists of the complete list of DSM-IV AD/HD symptoms, a screen for other disruptive behavior disorders, anxiety and depression, and ratings of academic and classroom behavior performance. Teachers in one suburban county completed the scale for their students during 2 consecutive years. Statistical methods included (a) exploratory and confirmatory latent variable analyses of item data, (b) evaluation of the internal consistency of the latent dimensions, (c) evaluation of latent structure concordance between school year samples, and (d) preliminary evaluation of criterion-related validity. The instrument comprises four behavioral dimensions and two performance dimensions. The behavioral dimensions were concordant between school years and were consistent with a priori DSM-IV diagnostic criteria. Correlations between latent dimensions and relevant, known disorders or problems varied from .25 to .66.     

Positive and negative contrast as a function of component duration for key pecking and treadle pressing

Pigeons responded on several multiple schedules for food reinforcers. The duration of the components varied from four seconds to 16 minutes. The absolute size of positive (Experiment 1) and negative (Experiment 2) behavioral contrast varied inversely with component duration when key pecks produced the reinforcers. The absolute size of negative contrast varied directly with component duration, when treadle presses produced the reinforcers (Experiment 3). These results conform to theories that suggest that positive and negative contrast are symmetrical when pigeons peck keys. They also conform to theories that suggest that the same principles do not govern contrast when pigeons peck keys as when they press treadles. Finally, the results support the measurement of behavioral contrast by the differences between baseline rates of responding and the rates emitted when contrast is present.     

Feedback functions for variable-interval reinforcement

On a given variable-interval schedule, the average obtained rate of reinforcement depends on the average rate of responding. An expression for this feedback effect is derived from the assumptions that free-operant responding occurs in bursts with a constant tempo, alternating with periods of engagement in other activities; that the durations of bursts and other activities are exponentially distributed; and that the rates of initiating and terminating bursts are inversely related. The expression provides a satisfactory account of the data of three experiments.     

青少年人格、人口学变量与主观幸福感的关系模型

采用分层随机抽样的方法,抽取了379名中学生和大学生样本,在多元相关分析的基础上,结合文献分析,采用结构方程建模技术,探讨了我国青少年学生人口学变量、人格维度和主观幸福感(SWB)的结构关系。结果表明,人口学变量中的年级和经济状况变量既与SWB有直接的关系,又通过大五人格中的神经质维度或外倾性维度对SWB有间接的效应,其中,经济状况对主观幸福感的正面效应较大,而性别和城乡变量则仅通过神经质和外倾性对SWB有微弱的间接效应;大五人格维度中,宜人性与SWB没有显著关系,开放性和严谨性通过神经质或外倾性与SWB存在间接效应,神经质和外倾性则对SWB有较强的直接预测力;结构方程模型验证了人格、人口学变量与SWB的这种关系。     

运用回归旋转设计研究倒摄抑制的实验研究

用回归旋转设计研究倒摄抑制。实验数据最后用二次方程逼近并取得拟合检验的显著性水平(P<0.01)。本实验揭示了(1)影响倒摄抑制的四个因素中,先前材料的学习程度(A)和后继学习材料的长度(C)这两个因素起主要作用。当A足够时,不论C的长短,倒摄抑制相对而言总是最小。这说明A因素起最主要作用;(2)在A足够的前提下,C因素与倒摄抑制成正比函数关系。本研究的成功实验表明,回归旋转设计不仅适用于心理学研究而且能揭示心理现象在多因素共同作用下变化的函数关系。因此,它比心理学研究的传统设计方法又前进了一步。     

主题关系在4~5岁儿童不同属性归纳推理发展中的作用

为探讨主题关系在儿童归纳推理中的作用,采用经典的三角归纳范式,设计了主题关系和知觉相似冲突、主题关系和分类学关系冲突两种情形,来考察4~5岁儿童在内在属性和情境性属性任务中的归纳推理。结果显示：当主题关系和知觉相似冲突时,从4.5岁开始儿童主要基于主题关系对情境性属性进行归纳推理,而对于内在属性的推论,4~5岁儿童在基于主题关系和基于知觉相似上没有显著差异。当主题关系和分类学关系冲突时,从4.5岁开始儿童主要基于主题关系对情境性属性进行归纳推理,从5岁开始儿童主要基于分类学关系对内在属性进行归纳推理。两个实验结果均发现5岁和5.5岁儿童能够依据不同的属性使用不同的关系推理,表现出归纳灵活性     

注意对拓扑性质和局部几何性质检测的不同影响──进一步的实验证据

实验研究了中央和外周提示信号对辨别朝向的任务（局部几何性质检测）和辨别有或无的任务（拓扑性质检测）的影响。结果表明,对于两种提示信号,在提示有效和提示无效条件下,辨别有或无比辨别朝向具有较短的反应时和较低的错误报告率;辨别朝向的ＲＴ和错误报告率都受提示信号的影响;而对于辨别有或无的任务,只有ＲＴ受提示信号的影响;提示信号对辨别朝向的影响比辨别有或无的影响大。本实验排除了对Ｈａｎ和Ｃｈｅｎ的实验的可能的光通量解释,并为提示信号对不同几何性质检测的不同影响提供了进一步的实验证据。