Teacher and Classroom Context Effects on Student Achievement: Implications for Teacher Evaluation

The Tennessee Value-Added Assessment System (TVAAS) has been designed to use statistical mixed-model methodologies to conduct multivariate, longitudinal analyses of student achievement to make estimates of school, class size, teacher, and other effects. This study examined the relative magnitude of teacher effects on student achievement while simultaneously considering the influences of intraclassroom heterogeneity, student achievement level, and class size on academic growth. The results show that teacher effects are dominant factors affecting student academic gain and that the classroom context variables of heterogeneity among students and class sizes have relatively little influence on academic gain. Thus, a major conclusion is that teachers make a difference. Implications of the findings for teacher evaluation and future research are discussed.     

Using Multilevel Regression Mixture Models to Identify Level-1 Heterogeneity in Level-2 Effects

This article proposes a novel exploratory approach for assessing how the effects of Level-2 predictors differ across Level-1 units. Multilevel regression mixture models are used to identify latent classes at Level 1 that differ in the effect of 1 or more Level-2 predictors. Monte Carlo simulations are used to demonstrate the approach with different sample sizes and to demonstrate the consequences of constraining 1 of the random effects to 0. An application of the method to evaluate heterogeneity in the effects of classroom practices on students is used to show the types of research questions that can be answered with this method and the issues faced when estimating multilevel regression mixtures.     

Unionization and the canadian university: Historical and personal observations

In 1949–50 Canadian professors, reacting to historically low salaries and inadequate pensions, founded the Canadian Association of University Teachers. Although its early concerns were economic, by the late 1950s the interest of the organization was spreading to issues of academic freedom and tenure and, related to it, university government. Having opened a national office in Ottawa, the CAUT soon championed an increased role for professors in governing their institutions. The bookA Place of Liberty (Whalley, 1964) eloquently made the claim for faculty empowerment. This movement also gained strength from the shortage of qualified staff in the 1960s and the resulting need of universities to improve terms and conditions of employment. Although faculty involvement in governance grew, by the mid-1970s many faculty members were embracing faculty unionization. This initiative had for years repelled most professors because it seemed unprofessional. However, deteriorating finances created a condition in which especially junior staff turned to faculty unions for protection. Not all Canadian universities became unionized. In spite of dire warnings about the effects of unionization, it does not seem that unionized universities today offer less scope for faculty participation in governance than the non-unionized.     

The role of cognitive style in educational computer conferencing

This paper reports an investigation of the impact of students’ cognitive style on their effective use of educational text‐based computer‐mediated conferences. The research centres on an empirical study involving students from three courses run by the British Open University. Statistical analysis of the data does not suggest that cognitive style has a strong influence on student participation in the conference, but does suggest that, contrary to expectations, ‘imagers’ may send more messages to conferences than ‘verbalisers’. The data also suggest a possible link between certain cognitive styles and course completion, and that the interaction of different styles within a group, as described by Riding and Rayner's (1998 ) team roles, may have an indirect influence on task completion.     

Sensitivity Analysis of the No-Omitted Confounder Assumption in Latent Growth Curve Mediation Models

Latent growth curve mediation models are increasingly used to assess mechanisms of behavior change. For latent growth mediation model, like any another mediation model, even with random treatment assignment, a critical but untestable assumption for valid and unbiased estimates of the indirect effects is that there should be no omitted variable that confounds indirect effects. One way to address this untestable assumption is to conduct sensitivity analysis to assess whether the inference about an indirect effect would change under varying degrees of confounding bias. We developed a sensitivity analysis technique for a latent growth curve mediation model. We compute the biasing effect of confounding on point and confidence interval estimates of the indirect effects in a structural equation modeling framework. We illustrate sensitivity plots to visualize the effects of confounding on each indirect effect and present an empirical example to illustrate the application of the sensitivity analysis.     

Language‐Focused Interventions on Math Performance for English Learners: A Selective Meta‐Analysis of the Literature

This meta‐analysis synthesized research on math performance outcomes for English learners (EL) as a function of language‐focused (math vocabulary) interventions. We included group and single‐subject design studies with children from kindergarten to 8th grade (3,766 students for group, 30 for single‐subject). Group studies yielded a mean Hedges’ g of 0.26 in favor of the interventions relative to the control conditions, whereas single‐subject studies yielded a mean Percentage of Non‐Overlapping Data of 81.01% and Phi coefficient of .66 relative to baseline. Although group studies yielded small effect sizes (ESs), we found significant moderators for grade level, intervention focus, and length of intervention. Single‐subject studies yielded higher ESs than group studies, and were considered generally effective, with a high ES. This finding was attributed to a direct focus on children with math difficulties and one‐to‐one instruction. The implications for practice and future research are discussed.     

The effect of ball-carrying technique and experience on sprinting in rugby union

There are several ways of carrying the ball in rugby union, which could influence the speed at which a player can run. We assessed 52 rugby players (34 males, 18 females) during a maximum sprint over 30 m without the ball, with the ball under one arm, and with the ball in both hands. Timing gates were used to measure time over the initial 10 m and the last 20 m. It has previously been reported (Grant et al., 2003) that running with the ball produces a slower sprinting speed than running without the ball. We hypothesized that the decrease in speed caused by carrying the ball would become less marked with the experience of the player. The male and female players were each divided into two groups: a "beginner" group that consisted of players in their first or second season and an "experienced" group that was composed of players who had played for more than two seasons. A 2 x 3 mixed-model analysis of variance was used to identify differences (P < 0.01) between the beginner and experienced groups in the three sprinting conditions. The times for the males for the first 10 m sprints without the ball, with the ball under one arm, and with the ball in both hands were 1.87 +/- 0.08 s, 1.87 +/- 0.08 s, and 1.91 +/- 0.1 s for the beginners, and 1.87 +/- 0.1, 1.88 +/- 0.1 and 1.88 +/- 0.12 for the more experienced players respectively. The times for the females for the first 10 m without the ball, with the ball under one arm, and with the ball in both hands were 2.13 +/- 0.16 s, 2.19 +/- 0.17 s, and 2.20 +/- 0.16 s for the beginners, and 2.03 +/- 0.12 s, 2.03 +/- 0.09 s, and 2.04 +/- 0.1 s for the more experienced players respectively. For the last 20 m of the 30-m sprint, there were differences between the different sprint conditions (P < 0.001) but no differences that were attributable to experience (P = 0.297). The times for the males over the last 20 m without the ball, with the ball under one arm, and with the ball in both hands were 2.58 +/- 0.19 s, 2.61 +/- 0.12 s, and 2.65 +/- 0.12 s for the beginners, and 2.59 +/- 0.12, 2.62 +/- 0.23, and 2.65 +/- 0.18 s for the more experienced players respectively. The times for the females over the last 20 m without the ball, with the ball under one arm, and with the ball in both hands were 3.25 +/- 0.38 s, 3.35 +/- 0.42 s, and 3.40 +/- 0.46 s for the beginners, and 3.04 +/- 0.32 s, 3.06 +/- 0.22 s, and 3.13 +/- 0.27 s for the more experienced players respectively. No gender-specific differences were detected. The results of this study suggest that practising sprints while carrying a ball benefits the early phase of sprinting while carrying the ball.