This digest addresses the role of evaluation and its basic logic, and provides a description of how the field is structured. In order to reach evaluative conclusions it is usually necessary to establish or identify factual promises and value premises. To obtain the required kind of overall evaluative conclusion, it is typically necessary to…

Meta-analysis is a collection of systematic techniques for resolving apparent contradictions in research findings. Meta-analysts translate results from different studies to a common metric and statistically explore the relations between study characteristics and findings. Since G. Glass first used the term "meta-analysis" in 1976, it has…

This digest provides an overview of several meta-analysis studies which focused on various aspects of science instruction. These studies examined: productive factors in science learning for grades 6 through 12; quality and quantity of instruction; effects of various teaching strategies on science achievement; instructional systems in science…

The first science education digest for 1985 focused on data obtained by use of meta-analysis techniques on research studies of science instruction. Instruction seldom takes place without instructional materials, so this second digest is a companion one containing a discussion of science education research on instructional materials. Data are shown…