This best-selling book has been carefully revised, updated, and expanded. New materials include discussion of the debate in evaluation between qualitative and quantitative research (Chapter 1), more on the role of theory in doing good case studies (Chapter 2), more extensive discussion of triangulation as a rationale for multiple sources of evidence (Chapter 4), and inclusion of program logic models as another analytic option (Chapter 5). In addition, the text has many updated examples, including ones dealing with international trade and world economy--topics of increasing visibility. In addition to these enhancements, the second edition of this volume still retains virtually all of the features and coverage of the original text.