Document Type



Throughout the 25-year history of research on stimulus
equivalence, one feature of the training procedure has remained
constant, namely, the requirement of operant responding during
the training procedures. The present investigation compared the
traditional match-to-sample (MTS) training with a more recent
respondent-type (ReT) procedure. Another consistent feature of
the equivalence paradigm is the apparent stipulation that both
training and testing must occur before equivalence emerges. In
this respect, a more idiosyncratic measure of class acquisition
would be desirable. Multidimensional scaling, as a class of
exploratory techniques, is introduced as a possible addition to the
stimulus equivalence paradigm.
Results from 35 subjects in 3 experiments suggest that while
the respondent-type training method can be an effective
procedure, the operant-based match-to-sample method was
clearly more effective in tests for symmetry, equivalence, and
extended equivalence. The addition of a scaling procedure proved
valuable and showed that both training methods facilitated the
emergence of derived relations to varying degrees. Results are
evaluated in relation to the importance of broadening the
necessary and sufficient training conditions and response
requirements for the emergence of stimulus equivalence.