A precursor to the relational evaluation procedure: Searching for the contextual cues that control equivalence responding

The precursor to the relational evaluation procedure (pREP) is a go/no-go s uccessive discrimination procedure for examining stimulus equivalence. Prev ious research has shown that it does not readily produce equivalence respon ding unless some matching-to-sample (NITS) procedures are incorporated into the experimental sequence. Two experiments attempted to identify contextua l cues that would generate equivalence responding on the pREP. Experiment 1 examined the effects of using abstract symbols or various verbal labels as response options on the pREP. Only the words same and different, When used as response options, reliably produced equivalence responding across 4 sub jects. Experiment 2 examined different pretraining preparations designed to attach the functions of the words same and different to abs tract symbols that could then be used as response options on the pREP. The most effective pretraining procedure involved multiple-exemplar training during which sub jects were trained to respond to abstract symbols in the presence of pairs of stimuli that were either formally the same or different. The abstract sy mbols were subsequently used as response options with the pREP, and all sub jects reliably demonstrated equivalence responding. The findings suggest th at the relations of same and different may be fundamental to equivalence re sponding. These findings are discussed in terms of what they suggest about the nature of the equivalence phenomenon specifically and derived relationa l responding more generally.