A study of effective training programs for community and court interpreters is reported. The characteristics of 25 well-established interpreter training programs in North America, Europe, and Scandinavia were examined, and 6 of these programs were selected for site visits. The purposes were to identify outstanding models of interpreter training, learn how they are organized, staffed, and funded, and find evidence that formal interpreter training significantly improves interpreter performance and helps ensure clients equal access to medical, legal, and social services. The report provides background information on the Twin Sisters Interpreter Project (Minnesota) and on the study itself, outlines its methodology, describes 8 of the training programs in some detail, presents results of an analysis and comparison of characteristics of the 25 programs examined, and makes observations on the importance of interpreter training in promoting professionalism, role definition, and reliability of performance. It is concluded that the proficiency and reliability of a given interpreter can not be assumed without a formal performance evaluation and that interpreter training programs can significantly affect an individual's interpreting proficiency. Appended materials include a summary of interviews and observations from the site visits, documentation on the training programs in the study, and additional information about community interpreting. (MSE)