A technique for efficiently presenting a large number of vocabulary items was developed for the testing of vocabulary comprehension in children younger than two years. The technique, incorporating slides of real objects, had the advantages of maintaining the child’s attention, motivating task continuation, and overcoming the extraneous contextual cues of test materials. The subjects were 106 children aged 17 to 30 months from a wide range of social status groups, and from both English and Spanish language families. Results indicated significant stability over time as well as a significant relationship to maternal report. Analysis of errors suggested that comprehension develops similarly to production, in that simple nouns were the easiest items, verbs were more difficult, and modifiers and locatives were the most difficult. There were no significant main effects of sex or social status. However, specific environmental variables such as parental attitudes and playmate patterns were significantly correlated with test performance. More flexible family control systems and more interaction with peers were both associated with better vocabulary comprehension in firstborn children.
