Exploring the influence and application of Campbellian validitytypology in the theory and practice of outcome evaluation, thisvolume addresses the strengths and weaknesses of this oftencontroversial evaluation method and presents new perspectives forits use.
Editors Huey T. Chen, Stewart I. Donaldson and Melvin M. Markprovide a historical overview of the Campbellian typology adoption,contributions and criticism. Contributing authors proposestrategies in developing a new perspective of validity typology foradvancing validity in program evaluation including
* Enhance External Validity
* Enhance Precision by Reclassifying the CampbellianTypology
* Expand the Scope of the Typology

The volume concludes with William R. Shadish's spirited rebuttalto earlier chapters. A collaborator with Don Campbell, Shadishprovides a balance to the perspective of the issue with aclarification and defense of Campbell's work.

This is the 129th volume of the Jossey-Bass quarterly reportseries New Directions for Evaluation, an officialpublication of the American Evaluation Association.