Field experiments in education frequently assign entire groups such as schools to treatment or control conditions. These experiments incorporate sometimes a longitudinal component where for example students are followed over time to assess differences in the average rate of linear change, or rate of acceleration. In this study, we provide methods…

In the "individually randomized group treatment" (IRGT) experimental design, individuals are first randomly assigned to a treatment arm or a control arm, but then within each arm, are grouped together (e.g., within classrooms/schools, through shared case managers, in group therapy sessions, through shared doctors, etc.) to receive…

This study aimed to determine the effect of mastery learning model supported with reflective thinking activities on the fifth grade medical students' academic achievement. Mixed methods approach was applied in two samples (n = 64 and n = 6). Quantitative part of the study was based on a pre-test-post-test control group design with an experiment…

In a pilot study at El Centro College, an urban college in the Dallas County Community College District, students in a new-to-college educational framework class were offered an intervention intended to enhance the academic advising process. The intervention consisted of in-class career services advising, degree selection, degree planning, course…

Previous work on statistical power has discussed mainly single-level designs or 2-level balanced designs with random effects. Although balanced experiments are common, in practice balance cannot always be achieved. Work on class size is one example of unbalanced designs. This study provides methods for power analysis in 2-level unbalanced designs…

The National Job Corps Study was conducted in 1994-1996 to provide a thorough and rigorous assessment of the impacts of the Job Corps on key participant outcomes. To ensure that the study was well implemented, a study team from Mathematica Policy Research, Inc., (MPR) investigated outcome and admission (OA) procedures in each Job Corps region and…