Single Case and Idiographic Research: Introduction to the Special Issue

Our goal in organizing this special issue focused on single case and idiographic research is to highlight the important scientific contributions that the study of the single case and the use of idiographic methods can make to our field. Single case investigations hold an important place in the history of behavior research and therapy, as described in the paper by Onghena et al. in this series, but have been largely supplanted by group designs. However, the pendulum appears to be swinging back toward the study of the single case. It is unlikely to be a coincidence that the increased interest in the single case comes at a time when the National Institutes of Health (NIH) have called for an increased emphasis on personalized health care (Hamburg & Collins, 2010), and strategy 3.2 of the National Institute of Mental Health's (NIMH) Strategic Plan calls for mental health researchers to expand and deepen the focus on personalized intervention research. We welcome this increased focus on idiographic methods and approaches to treatment, and we aim to support it with the collection of articles we have gathered here.