Number of Subjects and Time Points Needed for Multilevel Time-Series Analysis: A Simulation Study of Dynamic Structural Equation Modeling

Dynamic structural equation modeling (DSEM) is a novel, intensive longitudinal data (ILD) analysis framework. DSEM models intraindividual changes over time on Level 1 and allows the parameters of these processes to vary across individuals on Level 2 using random effects. DSEM merges time series, structural equation, multilevel, and time-varying effects models. Despite the well-known properties of these analysis areas by themselves, it is unclear how their sample size requirements and recommendations transfer to the DSEM framework. This article presents the results of a simulation study that examines the estimation quality of univariate 2-level autoregressive models of order 1, AR(1), using Bayesian analysis in Mplus Version 8. Three features are varied in the simulations: complexity of the model, number of subjects, and number of time points per subject. Samples with many subjects and few time points are shown to perform substantially better than samples with few subjects and many time points.     

Effects of disfluency and test expectancy on learning with text

Do students learn better with texts that are Open image in new window (i.e., disfluent)? Previous research yielded discrepant findings concerning this question. To clarify these discrepancies, the present study aimed at identifying a boundary condition that determines when disfluent text is, and is not, beneficial to learning. This boundary condition is knowledge about whether a test will follow (high test expectancy) versus not (low test expectancy). Participants with high test expectancy may already engage in effortful processing, so that making text harder-to-read (disfluent) might not change their processing mode any further. Thus, particularly when no test is expected, disfluency is supposed to exert its beneficial effect. This assumption was tested in a 2?×?2 design (N?=?97) with text legibility (fluent vs. disfluent) and test expectancy (low vs. high) as factors, and learning outcomes (retention, transfer) and learning times as main dependent variables. Results revealed that high test expectancy led to better learning outcomes (for retention and transfer), but disfluent text did not. Unlike expected, there was no interaction between the two factors. Moreover, both high test expectancy and disfluency led to longer learning times, resulting in a lower efficiency when learning with disfluent compared to fluent text. Hence, the present results further question the stability and generalizability of a positive disfluency effect on learning, because only high test expectancy – but not disfluency - stimulated better learning through more effortful processing the way it was supposed to.     

The Validity of Comparative Educational Studies

What are the conditions that will allow for appropriate comparisons among groups" Should the concept of comparative validity be added to the lexicon of the psychometrician"     

Expressive Vocabulary Predicts Nonverbal Executive Function: A 2-year Longitudinal Study of Deaf and Hearing Children

Numerous studies suggest an association between language and executive function (EF), but evidence of a developmental relationship remains inconclusive. Data were collected from 75 deaf/hard-of-hearing (DHH) children and 82 hearing age-matched controls. Children were 6–11 years old at first time of testing and completed a battery of nonverbal EF tasks and a test of expressive vocabulary. These tasks were completed again 2 years later. Both groups improved their scores on all tasks over this period. DHH children performed significantly less well than hearing peers on some EF tasks and the vocabulary test at both time points. Cross-lagged panel models showed that vocabulary at Time 1 predicted change in EF scores for both DHH and hearing children but not the reverse.     

Kinematic differences of elite and high-performance tennis players in the cross court and down the line forehand

This study identified and compared the full body kinematics of different skill levels in the forehand groundstroke when balls were hit cross court and down the line. Forty-three three-dimensional retroreflective marker trajectories of six elite and seven high-performance players were recorded using an eight-camera 400 Hz, Vicon motion analysis system. The six highest horizontal velocity forehands with reliable kinematics of all participants were analysed for each specific situation (a total of 156 analysed shots). Significant differences (p < 0.01) and large effect sizes were observed between elite and high-performance players in linear velocity of the shoulder (2.0 vs. 1.2 m/s), angular velocity of the pelvis (295 vs. 168 degrees/s), and angular velocity of the upper trunk (453 vs. 292 degrees/s) at impact. The elite group showed a tendency towards higher racquet velocities at impact (p < 0.05). No significant differences were found in angular displacement of the racquet, hip alignment, or shoulder alignment at the completion of the backswing; nor did angular displacement vary significantly at impact. Irrespective of the group, different shoulder, hip, and racquet angles were found at impact, depending on the situation. The results should assist coaches when striving to improve their players' forehand.     

Will Undergraduate Students Play Games to Learn How to Conduct Library Research?

This exploratory study examines whether undergraduate students will play games to learn how to conduct library research. Results indicate that students will play games that are an integral component of the course curriculum and enable them to accomplish overall course goals at the same time they learn about library research.     

The syllable frequency effect in visual recognition of French words: a study in skilled and beginning readers

The present study addressed the issue of syllable activation during visual recognition of French words. In addition, it was investigated whether word orthographic information underlies syllable effects. To do so, words were selected according to the frequency of their first syllable (high versus low) and the frequency of the orthographic correspondence of this syllable (high versus low). For example, the high-frequency syllable /ã/ is frequently transcribed by the orthographic cluster an, but infrequently transcribed by han in French. A lexical decision task was performed by skilled readers (Experiment 1) and beginning readers in Grade 5 (Experiment 2). Results yielded an inhibitory effect of syllable frequency in both experiments. Moreover, the reliable interaction between syllable frequency and orthographic correspondence frequency indicated that the syllable frequency effect was influenced by orthographic characteristics of syllables. Finally, data showed that the interaction between phonological and orthographic variables was modified with reading experience. The results are discussed in current models of visual word recognition.     

Aid effectiveness in education: Why it matters

This article introduces the special issue of Prospects on “Aid effectiveness in education”. It brings together case studies of attempts in several very different contexts to improve the effectiveness of the use of aid in the education sector. By drawing on the historical evolution of the new paradigm over the last 20 years, the authors make the case for a closer focus on aid’s effectiveness in education, as well as the need to reform the aid effectiveness architecture. In particular, they identify two major obstacles that need to be overcome to improve aid’s effectiveness in education: the lack of sufficient institutional and staff incentives for coordinated and harmonized behaviour; and factors that lead to risk-aversion and discourage innovation in delivering aid effectively.     

Beliefs about knowledge and knowing and multiple‐text comprehension among upper secondary students

Using a sample of 282 Norwegian upper secondary students, we examined whether two dimensions of topic‐specific epistemic beliefs, concerning the certainty of knowledge and the justification for knowing, predicted students' understanding of seven texts representing partly conflicting views on climate change. Text comprehension was measured at three different levels. Topic knowledge and topic interest were included in the analyses as control variables. Hierarchical regression analyses showed that students' beliefs about justification for knowledge positively predicted text comprehension at all three levels. That is, students believing that knowledge claims about climate change should be based on rules of inquiry and the evaluation and integration of multiple information sources did better on the three comprehension measures.