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…

Criticizes an earlier essay that questioned the validity of contemporary educational research practices, especially those involving experimentation. Argues that research using experimentation is valid and can lead to new and generalizable knowledge. (FMW)

Suggests that experimental studies are valuable in analyzing children's language development. Criticizes the scarcity of experimental and naturalistic investigation into preschool language development. Calls for long-term study of continuity and discontinuity in children's school and home learning and between different school stages. Observes that…

Laboratory simulations combine the strengths of lab experiments and field studies while avoiding many of their liabilities. They permit the emotional involvement, the time needed for development of norms and interlocked systems of interaction, and the broad range of variables typical of field settings, yet allow for experimental controls and…

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…