Joel Crohn, Ph.D., is a trained PREP psychologist who specializes in working with Jewish and interfaith couples and is the author of Mixed Matches. Howard Markman, Ph.D., and Susan Blumberg, Ph.D., are marital experts who wrote the best-selling book Fighting for Your Marriage. Janice Levine, Ph.D., is a Jewish PREP trainer and therapist who teaches at Harvard Medical School.