The role of method in treatment effectiveness research: Evidence from meta-analysis.

• DOI: 10.1037/1082-989x.6.4.413
• Publication Date: 2005-10-04T19:28:30Z
• Authors: David B. Wilson; Mark W. Lipsey
• Keywords: Research Design

A synthesis of 319 meta-analyses psychological, behavioral, and educational treatment research was conducted to assess the influence study method on observed effect sizes relative that substantive features interventions. An index used estimate proportion size variance associated with various features. Study methods accounted for nearly as much variability in outcomes characteristics Type design operationalization dependent variable were largest variance. The a result sampling error about large interventions studied. These results underscore difficulty detecting outcomes, importance cautiously interpreting findings from single study, meta-analysis summarizing across studies.