Longitudinal social network studies can easily suffer from insufficient statistical power. Studies that simultaneously investigate change of network ties and change of nodal attributes (selection and influence studies) are particularly at risk because the number of nodal observations is typically much lower than the number of observed tie…

Inherent in applied developmental sciences is the threat to validity and generalizability due to missing data as a result of participant drop-out. The current paper provides an overview of how attrition should be reported, which tests can examine the potential of bias due to attrition (e.g., t-tests, logistic regression, Little's MCAR test,…

Measuring change in an educational or psychological construct over time is often achieved by repeatedly administering the same items to the same examinees over time. When the response data are categorical, item response theory (IRT) model can be used as the measurement model of a second-order latent growth model (referred to as LGM-IRT) to measure…

This paper describes and demonstrates a new online resource developed to help researchers proactively plan for student attrition: the Student Attrition Lookup Tool (SALT). With SALT, researchers can access student mobility estimates for different student and school subpopulations and for different transition periods from kindergarten to grade 12.…

Respondent incentives are widely used to increase response rates, but their effect on nonresponse bias has not been researched as much. To contribute to the research, we analyze an incentive experiment embedded within the third wave of the German household panel survey "Panel Labor Market and Social Security" conducted by the German…

Most longitudinal studies are plagued by drop-out related to variables at earlier assessments (systematic attrition). Although systematic attrition is often analysed in longitudinal studies, surprisingly few researchers attempt to reduce biases due to systematic attrition, even though this is possible and nowadays technically easy. This is…

In a randomized controlled trial, a decision needs to be made about the total number of subjects for adequate statistical power. One way to increase the power of a trial is by including a predictive covariate in the model. In this article, the effects of various covariate adjustment strategies on increasing the power is studied for discrete-time…

As any empirical method used for causal analysis, social experiments are prone to attrition which may flaw the validity of the results. This article considers the problem of partially missing outcomes in experiments. First, it systematically reveals under which forms of attrition--in terms of its relation to observable and/or unobservable…

Background: Epidemiological information on age-related cardiovascular disease in people with intellectual disability (ID) is scarce and inconclusive. We compared prevalence and incidence of cerebrovascular accident and myocardial infarction over age 50 in a residential population with ID to that in a general practice population. Method: Lifetime…

This document was produced by the authors based on their research for the report "School Completion: What We Learn from Different Measures of Family Background," and is an added resource for further information. This study relies on two main sources to analyse how Year 12 completion is related to disadvantage: the Longitudinal Surveys of…

The purpose of this quantitative correlation study was to find the relationship between the level of perceived servant leadership and the school leader job satisfaction in the North American Division (NAD) of Seventh-day Adventists P-12 schools. This quantitative correlation study utilized Laub's (1999) Organizational Leadership Assessment…

Teacher attrition is a threat to public education in the United States. However, little information exists regarding teacher attrition and its root causes in international schools. Research, such as Barnett and McCormick's (2004) "Leadership and Individual Principal-Teacher Relationships in Schools" and Rockoff's (2004) "The Impact…

With its critical assessments of scientific evidence on the effectiveness of education programs, policies, and practices (referred to as "interventions"), and a range of products summarizing this evidence, the What Works Clearinghouse (WWC) is an important part of the Institute of Education Sciences' strategy to use rigorous and relevant…

Site differences in treatment outcomes are not often highlighted when the results of multisite randomized clinical trials (MRCTs) are reported. The primary analyses of a 6-site MRCT, the Treatment of SSRI-Resistant Depression in Adolescents (TORDIA) study, showed substantial variation by site in the performance of a medication-only condition and a…

This report presents the results of an experiment conducted in Alabama beginning in the 2006/07 school year, to determine the effectiveness of the Alabama Math, Science, and Technology Initiative (AMSTI), which aims to improve mathematics and science achievement in the state's K-12 schools. This study is the first randomized controlled trial…