Prospective longitudinal data collection is an important way for researchers and evaluators to assess change. In school-based settings, for low-risk and/or likely-beneficial interventions or surveys, data quality and ethical standards are both arguably stronger when using a waiver of parental consent--but doing so often requires the use of…

Mathematics related affect turn from positive to negative during comprehensive school years worldwide. There is a clear need to find solutions to the problem. However, some gaps and problems appear in the methodologies and the common approaches used in the field. This article discusses five studies addressing affective development, challenges some…

Prior research suggests that summer learning loss among low-income children contributes to income-based gaps in achievement and educational attainment. We present results from a randomized experiment of a summer mathematics program conducted in a large, high-poverty urban public school district. Children in the third to ninth grade (N = 263) were…

This quasi-experimental and pre/posttest study was designed to examine whether fourth-grade students who engaged in collaboratively writing letters to 11th-grade students performed better on tests of conceptual understanding of a unit on force and motion than students who did not. The participants included 835 fourth-grade students and 416…

Robotics competitions for K-12 students are popular, but are students really learning and improving their STEM scores through robotics competitions? If not, why not? If they are, how much more effective is learning through competitions than traditional classes? Is there room for improvement? What is the best robotics competition model to maximize…

Background: Cluster-randomized experiments that assign intact groups such as schools or school districts to treatment conditions are increasingly common in educational research. Such experiments are inherently multilevel designs whose sensitivity (statistical power and precision of estimates) depends on the variance decomposition across levels.…