Establishing naming in typically developing two-year-old children as a function of multiple exemplar speaker and listener experiences.

Naming is a verbal developmental capability and cusp that allows children to acquire listener and speaker functions without direct instruction (e.g., incidental learning of words for objects). We screened 19 typically developing 2- and 3-year-old children for the presence of Naming for 3-dimensional objects. All 9 3-year-olds had Naming, and 8 of 10 2-year-olds lacked Naming. For the 2-year-old children who lacked Naming, we used multiple-probe designs (2 groups of 4 children) to test the effect of multiple exemplar instruction (MEI) across speaker and listener responses on the emergence of Naming. Prior to the MEI, the children could not emit untaught listener or speaker responses following match-to-sample instruction with novel stimuli, during which they had heard the experimenter tact the stimuli. After MEI with a different set of novel stimuli, the children emitted listener and speaker responses when probed with the original stimuli, in the absence of any further instruction with those stimuli. Seven of 8 children acquired the speaker and listener responses of Naming at 83% to 100% accuracy. We discuss the basic and applied science implications.