Clinical practice as natural laboratory for psychotherapy research: a guide to case-based time-series analysis.

Both researchers and practitioners need to know more about how laboratory treatment protocols translate to real-world practice settings and how clinical innovations can be systematically tested and communicated to a skeptical scientific community. The single-case time-series study is well suited to opening a productive discourse between practice and laboratory. The appeal of case-based time-series studies, with multiple observations both before and after treatment, is that they enrich our design palette by providing the discipline another way to expand its empirical reach to practice settings and its subject matter to the contingencies of individual change. This article is a user's guide to conducting empirically respectable case-based time-series studies in a clinical practice or laboratory setting.