Classroom researchers are frequently urged to provide evidence of the reliability of their data. In the case of observational data, three approaches to this have emerged: observer agreement, generalizability theory, and measurement error. Generalizability theory provides the most powerful approach given an adequate data collection design, but…

Educators designing procedures for identifying students as learning disabled are faced with serious technical difficulties. A student with a learning disability is one who "has a severe discrepancey between achievement and intellectual ability" in one or more designated areas. The methods of quantifying achievement, intellectual ability,…