Explains the characteristics and importance of random assignment in experimental research on education. Considers factors supporting causal inferences, the nature of "assignment units," differences between random sampling and random assignment, the characteristics of randomization tests, forms of random assignment, and effects of experimental…

The paper discusses a number of issues concerning the practical usefulness of cognitive psychology research, and presents a case study of pilot training methods to illustrate a model of research processes that produces outcomes which contribute to both basic and applied research goals. Research studies are described as varying in the degree to…