Lee, R., McComas, J. J., & Jawor, J. (2002).
The effects of differential and lag reinforcement schedules on varied verbal responding by individuals with autism.
Journal of Applied Behavior Analysis,
35, 391-402.
Variability has been shown to be a reinforceable dimension of
behavior. One procedure that has been demonstrated to increase
variability in basic research is the lag reinforcement schedule.
On this type of schedule, a response is reinforced if it differs
from a specified number of previous responses. Lag schedules are
rarely used, however, for increasing response variability in
applied settings. The purpose of the present study was to
investigate the effects of a lag schedule of differential
reinforcement on varied and appropriate verbal responding to
social questions by 3 males with autism. A reversal design with a
multiple baseline across subjects was used to evaluate the
effects of the lag schedule. During baseline, differential
reinforcement of appropriate responding (DRA) resulted in little
or no varied responding. During the intervention, a Lag 1
requirement was added to the DRA (Lag 1/DRA) resulting in an
increase in the percentage of trials with varied and appropriate
verbal responding for 2 of the 3 participants. In addition, an
increase in the cumulative number of novel verbal responses was
also observed for the same 2 participants. These results are
discussed in terms of reinforcement schedules that support
variability, generalization, and potential stimulus control over
varied responding.
DESCRIPTORS: _behavioral variability, lag reinforcement schedules,
verbal responding