Stepwise variable selection in factor analysis

It is very important to choose appropriate variables to be analyzed in multivariate analysis when there are many observed variables such as those in a questionnaire. What is actually done in scale construction with factor analysis is nothing but variable selection.In this paper, we take several goodness-of-fit statistics as measures of variable selection and develop backward elimination and forward selection procedures in exploratory factor analysis. Once factor analysis is done for a certain numberp of observed variables (thep-variable model is labeled the current model), simple formulas for predicted fit measures such as chi-square, GFI, CFI, IFI and RMSEA, developed in the field of the structural equation modeling, are provided for all models obtained by adding an external variable (so that the number of variables isp + 1) and for those by deleting an internal variable (so that the number isp – 1), provided that the number of factors is held constant.A programSEFA (Stepwise variable selection in Exploratory Factor Analysis) is developed to actually obtain a list of the fit measures for all such models. The list is very useful in determining which variable should be dropped from the current model to improve the fit of the current model. It is also useful in finding a suitable variable that may be added to the current model. A model with more appropriate variables makes more stable inference in general.The criteria traditionally often used for variable selection is magnitude of communalities. This criteria gives a different choice of variables and does not improve fit of the model in most cases.The URL of the programSEFA is http://koko15.hus.osaka-u.ac.jp/~harada/factor/stepwise/.     

On Judgments of Approximately Equal

Although precision is often important in quantitative judgment, sometimes, it is valuable to recognize that two quantities are roughly the same. Fuzzy‐trace theory suggests that approximately equal judgments rely on gist representations (i.e., meaningful fuzzy categories of quantity). We conducted three experiments to investigate approximately equal judgments with number pairs presented in different formats, both with and without semantic content (breast cancer statistics). In each study, the ratio of the smaller divided by larger number predicted approximately equal judgments. Experiment 1 also examined how knowledge of breast cancer, presentation format (frequencies vs. percentages), and differences in gist comprehension of breast cancer information influence fuzzy equality judgments. As predicted by the fuzzy‐trace theory concept of denominator neglect, approximately equal judgments were more sensitive, as measured by signal detection theory (SDT) analyses, when presented as percentages. In both experiments with breast cancer statistics, people were more likely to judge number pairs approximately equal when they were embedded in sentences about breast cancer, and breast cancer knowledge predicted increased perception of equality, when appropriately consistent with reliable sources, and increased judgment sensitivity. In Experiment 2, a simple intervention focusing on gist meaning increased source‐consistent approximately equal judgments, increased SDT judgment sensitivity, and decreased SDT response bias. In Experiment 3, using number pairs devoid of semantic context spanning four orders of magnitude, we further examined ratio similarity. Overall, more knowledgeable judges and those who better understood the gist of meaningful numbers were more likely to judge literally different numbers as “approximately equal” rather than make precise discriminations that were meaningless. Copyright © 2017 John Wiley & Sons, Ltd.     

4~8年级学生分数数量表征的准确性及形式

在分数学习中,分数数量表征是非常重要的方面。本研究利用数字线估计任务对四到八年级学生分数数量表征的情况进行探索。研究结果表明：随着年级升高,被试分数数量表征的准确性也随之提高;被试对单位分数和非单位分数表征的准确性存在显著差异,表现为对单位分数表征的准确性显著高于对非单位分数的表征,这种差异在低年级显著,随着年级的增长,差异逐渐消失;四到八年级学生在0~3数字线上,对分数数量的表征表现为线性形式而非对数形式,且这种线性表征形式是在六年级开始出现并随着年龄增长逐渐发展起来的。中西方儿童在分数数量表征的准确性和形式上有相似的发展路径,但是在表征准确性上中国儿童更高、线性形式出现年级上中国儿童可能更早。     

时间赋义对数字空间表征的影响：来自数字线估计任务的证据

数字线估计任务的大量研究以纯数字为研究对象而忽视了赋义数字。本研究以Siegler等的数字线估计任务为原型,探讨在对数字时间赋义条件下小学二、四和六年级儿童的数字表征形式是否发生变化。结果表明,小学二年级是0-1000范围内数字表征从对数形式转换为线性形式的转折点,对数字赋予时间含义后,三个年级均出现了赋义效应。在线性模型和对数模型中时间赋义的作用相反,时间赋义表现出抑线升对（抑制线性模型提升对数模型解释力）的效果。     

时间知觉与估计的认知理论综述

本文回顾时间知觉与估计的实验研究 ,总结该领域的国内外研究结果 ,对该领域的各主要认知模型作了较全面的考察和评述 ,并进一步探讨了时间认知领域研究的今后发展 ,尤其是时间知觉与估计研究的脑电研究思路。     

Testing for DIF in a model with single peaked item characteristic curves: The parella model

The PARELLA model is a probabilistic parallelogram model that can be used for the measurement of latent attitudes or latent preferences. The data analyzed are the dichotomous responses of persons to items, with a one (zero) indicating agreement (disagreement) with the content of the item. The model provides a unidimensional representation of persons and items. The response probabilities are a function of the distance between person and item: the smaller the distance, the larger the probability that a person will agree with the content of the item. This paper discusses how the approach to differential item functioning presented by Thissen, Steinberg, and Wainer can be implemented for the PARELLA model. Requests for the PARELLA software should be sent to Iec Progamma PO Box 841, 9700 AV Groningen, The Netherlands.     

短时距估计中的心理影响因素

使用单任务研究程序,预期式研究范式,以产生时距作为反应指标,通过两个实验考察短时距估计中的间断位置、间断时距和提示线索效应,探讨产生时距与等待时距的关系问题,揭示注意和间断期望对短时距估计的影响。研究结果表明, 间断实验中表现出极其显著的提示线索效应,间断位置（等待时距）效应显著,间断时距效应及间断位置与间断时距的交互效应不显著。由此得出：(1)注意是影响被试时间判断的主要因素,被试的产生时距随着等待时距的增加而延长。(2)被试对间断的期望显著地影响其时间估计行为,无间断实验条件下,间断期望有损于时间估计。     

Bootstrap区间估计在认知诊断模型误设中的应用

认知诊断模型选择是认知诊断评估中重要研究问题之一。在实际应用中实践者并不知道真正拟合数据的模型,通常会用模型拟合指标检验模型与数据的拟合程度。从测量结果质量来看,除保证模型与数据拟合之外,还需要重点评价模型诊断结果的信度和效度等。考虑到以往研究大都采用基于信息量的拟合指标去判定模型与数据的匹配性,本研究提出综合考虑模型拟合指标与信度指标用于模型选择或评价模型误设。考虑实验因素为真实模型或分析模型（DINA模型、G-DINA模型、R-RUM模型）、样本量、题量和属性个数,在五因素（3×3×2×2×2）实验设计条件下,比较Bootstrap区间估计的属性分类一致性信度平均数与标准误和常用的拟合统计量-2LL、AIC、BIC对正确模型的选择率。结果表明：-2LL在题目数量多的情况下表现较好,而AIC、BIC在被试量较大的情况下表现较好,在不同的研究条件下,-2LL、AIC、BIC的模型选择率很不稳定,而用Bootstrap法估计的属性分类一致性信度平均数和标准误在不同研究条件的模型选择率较稳定,总体表现较好。     

不同亚型ADHD儿童的视通道时距估计能力

本研究选取ADHD混合型儿童11名,ADHD注意缺损型儿童13名以及正常儿童15名,通过"平均估计长度"、"平均估计误差百分比"、"估计变异值"三个指标,考察不同亚型ADHD儿童在时距复制和言语估计上的稳定性和精确性。研究发现,在视觉刺激条件下,ADHD儿童的时距估计缺损并不受时距长度的影响;ADHD混合型儿童在多项任务中所表现的稳定性和精确性都差,而ADHD缺损型儿童只是稳定性差,说明ADHD混合型是ADHD中更严重的亚类型;ADHD儿童在时距估计任务中稳定性差,反映了其状态调节能力的落后。     

Temporal perception in closed-skill sports: An experimental study on expert swimmers and runners

The cognitive benefits of closed-skill sports practice have so far been scantily investigated. Here, we thus focused on the potential impact of swimming and running - two sports that highly rely on a precise control of timing - on time processing. To investigate the impact of these closed-skill sports on time perception and estimation, three groups of participants (for a total of eighty-four young adults) took part in the present study: expert swimmers, expert runners, and non-athletes. The ability to process temporal information in the milliseconds and seconds range was assessed through a time reproduction and a finger-tapping tasks, while a motor imagery paradigm was adopted to assess temporal estimation of sport performance in a wider interval range. We also employed the Vividness of Movement Imagery Questionnaire to assess the individual's ability of motor imagery. Results showed that closed-skill sports, specifically time-related disciplines, enhance motor imagery and time perception abilities. Swimmers were more accurate and consistent in perceiving time when compared to runners, probably thanks to the sensory muffled environment that leads these athletes to be more focused on the perception of their internal rhythm.