Young children's use of range-of-reference information in word learning

An important source of information about a new word's meaning (and its associated lexical class) is its range of reference: the number of objects to which it is extended. Ninety toddlers (mean age = 37 months) participated in a study to determine whether young children can use this information in word learning. When a novel word was presented with unambiguous lexical class cues as either a proper name (i.e. 'His name is DAXY') or an adjective (i.e. 'He is very DAXY'), toddlers interpreted it appropriately, regardless of whether it was applied to one or both members of a pair of identical-looking stuffed animals. They restricted a proper name to the designated animal(s); but they generalized an adjective from the labeled animal(s) to a new animal bearing the same property. However, when the word was presented with no specific lexical class cues (i.e. 'DAXY'), toddlers made significantly different interpretations, depending on the number of referents. When the word was applied to one animal, they restricted it to that animal (consistent with a proper name interpretation); when the word was applied to two animals, they generalized it to a new animal with the property (consistent with an adjective or a restricted count noun interpretation). Range-of-reference information thus provided toddlers with a default cue to the meaning (and associated lexical class) of a novel word.