Recent developments in single-subject methodology: methods for analyzing generalization, maintenance, and multicomponent treatments.
At the outset of this chapter we asked whether or not single-subject methodology has outlived its usefulness to behavior therapy. We did so because serious doubts have been expressed about the ability of single-subject methodology to address the salient issues of the day. This chapter allays many of these doubts. This chapter reveals that single-subject researchers are far from helpless when investigating generalization and maintenance and identifying the active (and inactive) components in their compound treatments. In fact, a number of powerful strategies are at their disposal--strategies that are not strangers to the armamentarium of single-case researchers. These strategies are in essence nothing more than extensions of the reversal, multiple baseline, and simultaneous and alternating-treatments designs. In the case of the assessment of generalization, these extensions involve little more than the inclusion of continuous measures (or regular probes) of untrained responses throughout the investigation. In the case of the assessment of maintenance, they involve the replacement of a comparison of two or more acquisition procedures with a comparison of two or more maintenance procedures. And in the case of the identification of active (and inactive) components of compound treatments, they involve the aggregation of the findings from a series of single-subject investigations. When the requirements of single-subject designs and their extensions cannot be met, investigators still have available a set of traditional group designs (e.g., factorial and additive designs) for attacking these same issues. Assessment of generalization, maintenance, and the components of compound treatments are not the only salient issues facing behavior therapy today. Another is the widening gap between the researcher and the practitioner (e.g., Barlow, 1980; Wilson, 1981). It is thought by some that single-subject methodology may be the means of bridging this gap; that through single-subject methodology a new breed of practitioner will appear: the empirical clinician (e.g., Barlow et al., 1984; Goldfried, 1984; Hayes, 1981). This new breed of practitioner will be made up of persons who, for economic and pragmatic reasons, are concerned with accountability and who use single-subject designs to achieve it (Barlow et al., 1984). The present chapter does little to help bridge the gap between the researcher and the practitioner; thus, the present chapter does little to help bring about the creation of this new breed of practitioner, the empirical clinician. In fact, the single-subject strategies described in these pages appear to be suitable for use only by the researcher.(ABSTRACT TRUNCATED AT 400 WORDS)