Problems typically stem from the respective natures of researchers and practitioners--each are concerned with their own domain of expertise and tend to feel constricted or threatened by the other. Working through these problems will require of both a shift in operating philosophy and methodology, as well as a commitment to collaboration. Each of the 11 chapters of this book has to do with a separate aspect of the evaluation of crime and delinquency programs: 1) Grounds for concern with evaluation; 2) Defining success or failure; 3) Choosing among alternative measures; 4) Assessing effort and attainment in monetary terms; 5) Resisting spurious evaluations; 6) Determining what clients to compare; 7) Obtaining data on treatment consequences; 8) Obtaining data on subjects and programs; 9) Combining measurements on subjects and programs; 10) Determining who should do the comparing; and 11) Making the knowledge gained by evaluative research cumulative. Tables, 106 references, 3 appendixes