Single-case designs, as a research methodology, have had a chequered history, in both the behavioural sciences and the medical field (where they are more commonly known as N-of-1 trials).  In part, this is due to confusion about what constitutes single-case methodology, as well as the poor standard of many studies reported in the literature.  An overview of some possible designs within single case research will be illustrated with examples from clinical practice.  More recently, the randomised N-of-1 trial has been classified as poroviding Level 1 evidence for treatment decision purposes.  As other disciplines embrace single-case methodology as a complement to the traditional between-groups design, the challenge is to make high quality single-case research, from whatever field, the standard of practice.  The present paper discusses the above issues and introduces a critical appraisal tol (The Risk of Bias in N-of-1 Trials Scale) that can be used as a practical guide for planning and conduction scientifically rigorous single-case research.

Presented by Professor Robyn Tate

The University of Sydney