ABSTRACT
Different methods are proposed for summarizing and integrating literature. These methods are not essentially contradictory; rather each may be appropriate under certain conditions with certain kinds and amounts of studies. Gage also is skeptical of criticisms of design and analysis flaws and provides some persuasive examples of spurious affectations of critics. There is no question that methodological carping, frequently on trivial issues which have little effect on outcomes, is endemic to social science research. On summarizing evaluation studies, meta-analysis requires the assumption that all of the programs included in the studies are identical in what they do. Jackson developed an instrument designed to code threats to internal and external validity out of the studies being summarized. Although not a device which can be routinely applied by any investigator, that instrument can serve as a sensitizer on what one ought to look for.
