Eighty-three studies from 1982 to 2001 with formal training interventions were integrated via meta-analytic techniques to determine the effectiveness of interventions in their enhancement of performance, knowledge, and expertise at the individual, team or group, or organizational level. The studies were separated by research design, with the outcome measure of the intervention as the unit of analysis. The effect size for knowledge outcomes ranged from .96 to 1.37; expertise outcomes from .35 to 1.01; and system outcomes averaged .39. Interventions with knowledge outcomes were found to be more effective than in the Burke and Day (1986) meta-analysis, with the most effective interventions using a single group pretest-posttest research design. Methodological and conceptual differences in Burke and Day's meta-analysis on the effectiveness of managerial training make historical comparisons risky. The data suggest that practitioners can attain substantial improvements in both knowledge and skills if sufficient front-end analysis is conducted to assure that the right development is offered to the right leaders.