Data collection can be the most time- and cost-intensive part of developmental research. This article describes some long-proposed but little-used research designs that have the potential to maximize data quality (reliability and validity) while minimizing research cost. In "planned missing data designs", missing data are used…

Measuring cognitive achievement gains in project evaluation is dealt with. This guide provides those concerned with project evaluation with the basic tools for conducting technically sound, interpretable evaluation studies. Exotic designs are avoided and five basic models which appear feasible to implement in real-world settings are focused on.…

Data on two preschool intervention programs for children from low-income families are discussed. The first program, the Karnes Preschool Program for the amelioration of learning deficits, is characterized by a structured format based on psychological theories. Its curriculum is designed to develop the basic language processes and to teach content…