What makes a word easy to acquire? The effects of word class, frequency, imageability and phonological neighbourhood density on lexical development

Abstract

This article analyses how a set of psycholinguistic factors may account for children's lexical development. Age of acquisition is compared to a measure of lexical development based on vocabulary size rather than age, and robust regression models are used to assess the individual and joint effects of word class, frequency, imageability and phonological neighbourhood density on Norwegian children's early lexical development. The Norwegian Communicative Development Inventories (CDI) norms were used to calculate each CDI word's age of acquisition and vocabulary size of acquisition. Lexical properties were downloaded from the lexical database Norwegian Words, supplemented with data on frequency in adult and child-directed speech. Age of acquisition correlated highly with vocabulary size of acquisition, but the new measure was more evenly distributed and more sensitive to lexical effects. Frequency in childdirected speech was the most important predictor of lexical development, followed by imageability, which seems to account for the dominance of nominals over predicates in Norwegian.

Validating the psycholinguistic aspects of LITMUS-CLT: Evidence from Polish and Norwegian

“…When it comes to lexical development, Goodman et al (2008), who investigated the lexical development of children acquiring American English, demonstrated that within a word class, young children acquire words earlier the more frequent they are. They found CDS frequency as a far better predictor of lexical development than frequency in speech between adults (Goodman et al, 2008); these findings were confirmed for Norwegian by Hansen (2016).…”

“…Word frequency affects both lexical processing (Bates et al, 2003;Strain & Herdman, 1999) and children's lexical development (Goodman et al, 2008;Hansen, 2016). Concerning processing, Bates et al (2003), who performed a picture naming task across seven different languages (English, German, Spanish, Italian, Bulgarian, Hungarian and Mandarin), reported a highly significant frequency effect on naming response time within all languages in adult native speakers.…”

“…As discussed, CDS frequency was initially considered as a background factor for CLT, but rejected because it could not be obtained for all the languages involved. However, there are available frequency lists for both languages investigated here, based on eight corpora and about 800,000 words for Polish (Haman, Etenkowski, et al, 2011) and two corpora and about 67,000 words for Norwegian (Hansen, 2016).…”

“…Both CDS frequency lists (Haman, Etenkowski, et al, 2011;Hansen, 2016) are skewed towards few occurrences, as frequencies tend to be, and hence logarithmically transformed (on the formula ln(x+1)). The…”

Subjective ratings of age-of-acquisition: exploring issues of validity and rater reliability

“…Indeed, considering the low imageability of function words (Bird et al, 2001), one may speculate that rating AoA of function words is a more difficult task than that of rating concrete nouns and verbs. It is, moreover, conceivable that the threshold for CDI-based AoA applied herepresent in 75% of children, as opposed to 50% in previous studies (Goodman et al, 2008;Hansen, 2017)could have affected validity scores. In the light of these complicating factors, the finding that some participants nonetheless meet the posited validity and reliability criteria is perhaps surprising.…”