Assessing lexicon: validation and developmental data of the Picture Naming Game (PiNG), a new picture naming task for toddlers

Background: Understanding lexical abilities in infants and toddlers is important, yet no single tool can be used. Aims: To perform a validation of a new tool (known as the Picture Naming Game, or 'PiNG') for assessing lexical comprehension and production in toddlers and to obtain developmental trends for Italian children. Methods & Procedures: PiNG consists of four subtests: Noun Comprehension (NC), Noun Production (NP), Predicate Comprehension (PC) and Predicate Production (PP), each containing 20 lexical targets. It was administered to 388 children with typical development aged 19-37 months. The short form of the Italian version of the MacArthur-Bates Communicative Development Inventories (MB-CDI), previously completed by parents of participants, was used for the validation of PiNG. Outcomes & Results: For the validation study, reliability, internal consistency and concurrent validity were analysed. The reliability was optimal for NC, NP and PP, and satisfactory for PC. Split-half analysis showed a fair internal consistency for all of the subtests. Concurrent validity was verified through the correlation with MB-CDI using Pearson's correlation coefficient, which was significant even after having controlled for age. To describe the developmental trends, data are provided for 1-month age intervals. The comprehension subtests showed a rapid increase at younger ages, with children reaching a plateau slightly earlier for the NC (at 30 months versus 33 months for the PC). The increase in the production subtests was gradual; PP appeared to be the most difficult subtest, administrable starting at the age of 24 months. When we analysed, as potential confounders for developmental trends, gender, parents' educational level, and the way in which the subtests were administered, no differences were found, except for a better performance for girls in the NP subtest. Conclusions & Implications: Overall, the results suggest that PiNG is suitable for children in the age range considered to evaluate language abilities. It can be used together with other tools with clinical and theoretical objectives also to describe lexical abilities in atypical populations, such as children with cognitive and/or language impairment, as well as with late-talking children. Finally, the four subtests can be administered separately or combined, which provides flexibility in clinical use, in that the individual child's linguistic and/or cognitive characteristics and level can be taken into consideration.