Effects of prior conditional discrimination training, symmetry, transitivity, and equivalence testing on the emergence of new equivalence classes

Prior studies have shown that the establishment of equivalence classes usin g the simple-to-complex protocol significantly enhanced the emergence of ot her new equivalence classes under the simultaneous protocol (yield). The cu rrent experiment showed how those enhancement effects were influenced by ea ch component of the protocol used to establish the initial equivalence clas ses. Yield during the simultaneous protocol was not improved following the prior establishment of other baseline conditional discriminations alone. Th e prior establishment of the conditional discriminations plus symmetry test ing produced a small increment in yield. The prior establishment of conditi onal discriminations plus transitivity testing produced a very large increm ent in yield. The prior establishment of conditional discriminations plus t ransitivity and symmetry testing, or symmetry, transitivity and equivalence testing (i.e., equivalence class formation) did not produce further increm ents in yield. Thus, the enhanced emergence of new equivalence classes unde r the simultaneous protocol was due to prior demonstrations of transitivity rather than to the prior establishment of other equivalence classes. Some possible behavioral processes responsible for these effects are discussed.