This volume -- the revised edition of -- covers the assessment of how a program design works in practice. It reflects the recent emphasis on qualitative methods, and discusses when qualitative or quantitative methods are more appropriate. The book illustrates that the evaluator's task is not to judge the adequacy of program implementation, but rather to document, describe, observe, or assess by some other means how a program is implemented. The text has been organized to reflect a natural and logical ordering of the steps of planning, data collection, and analysis. References have been updated and examples included from education, business, social services, and other non-profit settings.