Using the open-source statistical language R to analyze the dichotomous Rasch model

R, an open-source statistical language and data analysis tool, is gaining popularity among psychologists currently teaching statistics. R is especially suitable for teaching advanced topics, such as fitting the dichotomous Rasch model-a topic that involves transforming complicated mathematical formulas into statistical computations. This article describes R’s use as a teaching tool and a data analysis software program in the analysis of the Rasch model in item response theory. It also explains the theory behind, as well as an educator’s goals for, fitting the Rasch model with joint maximum likelihood estimation. This article also summarizes the R syntax for parameter estimation and the calculation of fit statistics. The results produced by R is compared with the results obtained from MINI STEP and the output of a conditional logit model. The use of R is encouraged because it is free, supported by a network of peer researchers, and covers both basic and advanced topics in statistics frequently used by psychologists.     

Learning as a task or a virtue: U.S. And Chinese preschoolers explain learning

The purpose of this study was to examine cultural influences on conceptual orientations of learning in U.S. and Chinese preschoolers. A sample of 188 preschoolers 4-6 years of age provided free-narrative responses to 2 story beginnings about the learning behavior of 2 protagonists, 1 who worked hard and 1 who gave up. Results showed that despite some differences in the younger age groups, children from both cultures valued learning similarly at age 6. However, important cultural differences emerged in children's construals of the learning process. U.S. children showed a heightened awareness of the mind/task attributes of the learner, that is, ability, task attempting, and strategy use. By contrast, Chinese children perceived more the learner's dispositional qualities of diligence, persistence, and concentration. These trends increased as children's age increased. The U.S. findings are interpreted as reflecting the U.S. cultural emphasis on learning as a task, and the Chinese results, as reflecting the Chinese cultural focus on learning as a process of cultivating personal virtue.     

Stability and variability may respond differently to changes in walking speed

In gait research it has often been assumed that variability and stability are negatively correlated, where increases in variability are assumed to equate with increases in instability. The purpose of this paper is to illustrate that variability does not always equate with stability. To proof this point, a method was developed to directly assess stability and variability during the application of a visual perturbation at different walking speeds. Walking variability was measured by using the average standard deviation of the knee joint angle across the gait cycle. Walking stability was measured by the recovery time of the knee joint angle trajectory from the distortion induced by a visual perturbation that was delivered at the beginning of the stance phase. Five participants were required to walk at six different velocities on a treadmill (0.67, 0.80, 0.94, 1.07, 1.21, and 1.34 m/s). The coefficients of intraclass correlations for the experiment were 83% and 80% for the calculated stability and variability, respectively. The calculated stabilities were not sensitive to changes in walking speed (p>0.98). The calculated variability however decreased with increases in walking speed (p=0.004). No significant correlation between variability and stability was observed (r=-0.002). We suggest that gait stability is independent of variability during locomotion and should thus be measured independently.     

青少年的人格特征与互联网信息服务使用的关系

互联网上的信息服务为青少年的个性化学习提供了可能,如何使青少年健康地进行网上冲浪,使他们在冲浪的过程中增强自律意识,就需要我们深入地了解互联网信息服务在哪些方面能够满足青少年的需要。该研究通过对339名中学生进行问卷调查,对青少年的人格特征、社会支持与互联网信息服务之间的关系进行了探讨,结果表明:(1)开放性、客观社会支持和对社会支持的利用对互联网信息服务的使用偏好有直接而显著的影响。(2)宜人性和外向性通过社会支持的三个方面间接地对互联网信息服务的使用偏好产生影响。(3)客观社会支持会影响主观社会支持,主观社会支持对社会支持的利用水平也有影响。     

非英语专业大学生短文写作元认知发展的一般特点

对1043名大学生(有效被试1012人)进行英文写作元认知、自我效能、成就目标、价值、内控性的测量,旨在了解非英语专业大学生英文写作元认知各维度的一般性发展特点。结果发现:语言策略、作文标准、准备性和计划性上存在年级差异;对作为作者的自己的优点的了解、对作为作者的自己的缺点的了解、语言策略知识、元认知体验、计划性、准备性、调节性上存在性别差异;在英文写作自我效能、价值、成就目标、内控性高分组与低分组间元认知水平差异达到显著性,且高分组具有较高的英文写作元认知水平。     

试论管仲人才思想中的民本因素--以《管子》为中心

民本思想是齐文化的重要组成部分,也是管仲施政思想的基石,其言论．行动中都展示着民本思想的精华。而体现管仲思想的《管子》一书,对人才思想有较系统的论述。本文试以管仲为例,以《管子》一书为中心,来探析其人才思想中的民本因素,即“任其所长,不任其所短”的人才原则,包括其产生原因、表现方式、对后世所带来的社会影响等。     

Solving combinatorial problems: The 15-puzzle

We present a series of experiments in which human subjects were tested with a well-known combinatorial problem called the 15-puzzle and in different-sized variants of this puzzle. Subjects can solve these puzzles reliably by systematically building a solution path, without performing much search and without using distances among the states of the problem. The computational complexity of the underlying mental mechanisms is very low. We formulated a computational model of the underlying cognitive processes on the basis of our results. This model applied a pyramid algorithm to individual stages of each problem. The model's performance proved to be quite similar to the subjects' performance.     

Gay adolescents and suicide: understanding the association

Suicide among gay adolescents is a major public health concern, but it is still under-emphasized within mainstream healthcare. This article brings together information garnered from past studies, articles, and experiences to create a more in-depth understanding of why gay adolescents are at a higher risk for suicide. By creating a better understanding, this article attempts to push forward the significance of this issue and encourages physicians to take a more active role in suicide prevention. The article initially explores why issues involving homosexuality are seldom discussed and provides evidence for an increased risk in suicide among gay adolescents. By addressing major psychosocial issues faced by gay adolescents, it spends the majority of time facilitating an understanding of the increased risk. In this article "gay" refers to homosexual males and females, and bisexuals unless otherwise indicated.