Applied research studies with single-subject designs: Why so few?

Abstract
In spite of several calls for increased use of single-subject designs for evaluating applied sport psychology interventions, studies using them rarely appear in our major sport psychology journals. On the assumption that some basic misunderstandings concerning these designs may have contributed to their lack of use, the present paper: (a) describes fundamental characteristics of all single-subject designs, (b) attempts to clarify potential misunderstandings concerning these designs, and (c) describes the alternating-treatments design—a strategy for comparing two or more treatments on an ongoing basis within individual athletes.