Cognitive/developmentalists and behaviour analysts have developed parallel
paradigms of relevance to the investigation of the exposure learning of vocabulary in three contexts: non-ostensive, ostensive, and fast mapping/exclusion. Researchers have claimed that young children are able to comprehend new words following a limited number of unreinforced exposures. However, methodological limitations of such studies render the researchers' conclusions equivocal: participants' accurate responses on comprehension tests may reflect false positive responses, and cognitive/developmental researchers have failed to demonstrate that word-referent relations acquired are symbolic, and thus linguistic. The behaviour analytic stimulus equivalence paradigm provides a methodology for assessing the symbolic properties of such relational responding. The present se1ies of studies thus investigates young children's
exposure learning of equivalence relations in rigorously controlled conditions.
Study 1 investigated the exposure learning of a single new word-object relation;
results highlighted the existence of false positive responding in such studies, and the necessity of exposing multiple relations. Studies 2 to 5 thus examined the exposure learning of two novel relations. Five children, aged 25 to 32 months, demonstrated the acquisition of word-referent relations following unreinforced non-ostensive, ostensive, or fast mapping/exclusion exposures; where tested, these children also demonstrated the derivation of symbolic -- equivalence -- relations. A history of conditional responding also facilitated some children's performances on subsequent test trials.
However, the majority of participants (17/22) failed comprehension and naming
tests. Given the paucity of methodological control implemented by cognitive/
developmentalists these results were not unexpected and question claims made by such researchers regarding the efficiency of exposure learning.