Exploring the set-theoretical structure of objects by additive trees

Arrangements of feature sets that have been proposed to represent qualitative and quantitative variation among objects are shown to generate identical sets of set-symmetric distances. The set-symmetric distances for these feature arrangements can be represented by path lengths in an additive linear tree. Imperfect versions of these feature arrangements are proposed, which also are indistinguishable by the set-symmetric distance model. The distances for the imperfect versions can be represented by path lengths in an additive imperfectly linear tree. When dissimilarities are defined by the more general contrast model and a constant may be added to proximity data, then for both the perfect and imperfect arrangements an additive tree analysis obtains a perfect fit with an imperfectly linear tree. However, in the case of the contrast model also the distinction between the perfect and imperfect arrangements disappears in that also for the perfect arrangements the resulting tree need no longer be linear.The author is grateful to Mathieu Koppen for detailed comments on an earlier version of this article.     

Training children's self-control: A field experiment in self-monitoring and goal-setting in the classroom

A field experiment investigated the effects of training in self-monitoring and goal-setting skills on classroom study behavior and academic achievement among elementary school students in an individualized mathematics program. In the Self-Monitoring Conditions, students were shown a simple system for observing and maintaining daily records of their own study behavior during their math classes; orthogonally, in the Goal-Setting Conditions, students were shown a simple method of setting and recording daily performance goals during their math classes. Exposure to self-monitoring procedures produced significant increases in both appropriate study behavior and in actual achievement in the mathematics program, while exposure to goal-setting procedures had no effect on either study behavior or academic achievement. Nor, contrary to expectation, did exposure to the goal-setting instructions enhance the effectiveness of the self-monitoring system. The implications of these results in terms of implicit and explicit models of self-reinforcement processes were discussed.     

Progressive changes in articulatory patterns in verbal apraxia: A longitudinal case study

This research reports findings in a 10-year study of an apraxic adult, who was one of five subjects described by Shankweiler and Harris, (Cortex, ,2 277–292, 1966). Confusion matrices and feature analysis were used to compare 1965 and 1975 performances. Results indicate that over the 10-year period, errors of place, manner, and omission were markedly reduced. Voicing errors, however, while reduced in total number, still constituted a significant percentage of the patient's residual errors. Implications of these findings are discussed.     

Syntactic influences on stuttering in young child stutterers

This study examined the location and rate of stuttering in the spontaneous speech of nine young stutterers (4.0–6.6 yr) in relation to certain aspects of syntax. It was designed to answer the following questions: Is there more stuttering at clause onset (boundary) than at other points in the clause? Does the type of clause influence rate of stuttering? Is there more stuttering on complex than on simple sentences? The syntactic analysis defined 10 clause types (seven pertaining to complex sentences and three pertaining to simple sentences); clause boundaries (taking into account “filler” words occuring in such positions); and hierarchical constituent structure within sentences. Stuttering was found with significantly greater frequency at clause boundaries than at internal (nonboundary) positions of clauses. This was apparent for nine of the 10 clause types, the exception being complement clauses. The word “and” at the beginning of simple and complex sentences provoked a high rate of stuttering. The hierarchical structure within the clause did not influence the location of stuttering, and sentence complexity was not a factor in the rate of stuttering.     

Toward an integrated approach to early childhood stuttering

This article proposes a model that integrates various factors influencing early childhood stuttering. The factors interact in a synergistic manner and can be subsumed under three macrofactors: physiological, psycholinguistic, and psychosocial. Such a model can be clinically applied toward an integrated approach to the assessment and treatment of the young stutterer.     

Single-Stage Prediction Models Do Not Explain the Magnitude of Syntactic Disambiguation Difficulty

The disambiguation of a syntactically ambiguous sentence in favor of a less preferred parse can lead to slower reading at the disambiguation point. This phenomenon, referred to as a garden-path effect, has motivated models in which readers initially maintain only a subset of the possible parses of the sentence, and subsequently require time-consuming reanalysis to reconstruct a discarded parse. A more recent proposal argues that the garden-path effect can be reduced to surprisal arising in a fully parallel parser: words consistent with the initially dispreferred but ultimately correct parse are simply less predictable than those consistent with the incorrect parse. Since predictability has pervasive effects in reading far beyond garden-path sentences, this account, which dispenses with reanalysis mechanisms, is more parsimonious. Crucially, it predicts a linear effect of surprisal: the garden-path effect is expected to be proportional to the difference in word surprisal between the ultimately correct and ultimately incorrect interpretations. To test this prediction, we used recurrent neural network language models to estimate word-by-word surprisal for three temporarily ambiguous constructions. We then estimated the slowdown attributed to each bit of surprisal from human self-paced reading times, and used that quantity to predict syntactic disambiguation difficulty. Surprisal successfully predicted the existence of garden-path effects, but drastically underpredicted their magnitude, and failed to predict their relative severity across constructions. We conclude that a full explanation of syntactic disambiguation difficulty may require recovery mechanisms beyond predictability.     

Model comparison of nonlinear structural equation models with fixed covariates

Recently, it has been recognized that the commonly used linear structural equation model is inadequate to deal with some complicated substantive theory. A new nonlinear structural equation model with fixed covariates is proposed in this article. A procedure, which utilizes the powerful path sampling for computing the Bayes factor, is developed for model comparison. In the implementation, the required random observations are simulated via a hybrid algorithm that combines the Gibbs sampler and the Metropolis-Hastings algorithm. It is shown that the proposed procedure is efficient and flexible; and it produces Bayesian estimates of the parameters, latent variables, and their highest posterior density intervals as by-products. Empirical performances of the proposed procedure such as sensitivity to prior inputs are illustrated by a simulation study and a real example.This research is fully supported by a grant from the Research Grant Council of the Hong Kong Special Administrative Region, China (Project No. CUHK 4346/01H). The authors are thankful to the Editor, the Associate Editor, and anonymous reviewers for valuable comments which improve the paper significantly, and grateful to ICPSR and the relevant funding agency for allowing use of the data in the example. The assistance of Michael K.H. Leung and Esther L.S. Tam is gratefully acknowledged.     

高校多媒体教学环境下的教-学-学习绩效关系的建模与分析

本文是在先前建立的多媒体教学环境下教师授课、学生学习和学习绩效的3个因素结构模型基础上,采用路径建模技术,建立了多媒体教学环境下教一学一学习绩效关系模型。基于对该路径模型的分析,获得如下结论：（1）多媒体教学中影响因素的主导作用是沿着学习者认知加工过程中的信息流而展开的;（2）对于学生在课堂中的信息加工,影响最大的因素是教师授课时对学生的能力培养,影响为其次的因素是教师的授课技术;（3）课件的良好界面信息设计对学生的知识掌握起重要作用;（4）诸如授课速度过快、信息量过大等多媒体教学中的易现问题会增加学生的外在认知负荷而降低学习效果;（5）在多媒体教学中,教师与学生都要注意学生学习风格来更好地进行教学或学习。