Pullin, A. S., & Knight, T. M. (2009). Data credibility: A perspective from systematic reviews in environmental management. In M. Birnbaum & P. Mickwitz (Eds.), Environmental program and policy evaluation: Addressing methodological challenges. New Directions for Evaluation, 122, 65–74. Data Credibility: A Perspective From Systematic Reviews in Environmental Management Andrew S. Pullin, Teri M. Knight Abstract To use environmental program evaluation to increase effectiveness, predictive power, and resource allocation efficiency, evaluators need good data. Data require sufficient credibility in terms of fitness for purpose and quality to develop the necessary evidence base. The authors examine elements of data credibility using experience from critical appraisal of studies on environmental interventions employing systematic review methodology. They argue that criti- cal appraisal of methodological quality is a key skill to improve both retro- spective evaluation and prospective planning of monitoring of environmental programs. Greater transparency and data sharing among evaluators could facil- itate rapid development in approaches to environmental evaluation that improve data credibility. © Wiley Periodicals, Inc. I f we want to know what works and what doesn’t, we collect data and analyze them. But the confidence with which we can interpret those data in the context of our questions depends on their quality and the strength of the evidence they provide (how credible they are). Is the measured effect 65 6 NEW DIRECTIONS FOR EVALUATION, no. 122, Summer 2009 © Wiley Periodicals, Inc., and the American Evaluation Association. Published online in Wiley InterScience (www.interscience.wiley.com) • DOI: 10.1002/ev.296