[show abstract][hide abstract] ABSTRACT: This study investigated the validity of tense and agreement productivity (TAP) scoring in diverse sentence frames obtained during conversational language sampling as an alternative measure of finiteness for use with young children.
Longitudinal language samples were used to model TAP growth from 21 to 30 months for 37 typically developing toddlers. Empirical Bayes (EB) linear and quadratic growth coefficients and child sex were then used to predict elicited grammar composite scores on the Test of Early Grammatical Impairment at 36 months.
A random effects quadratic model with no intercept best characterized TAP growth, replicating the findings of Rispoli, Hadley, and Holt (2009). The combined regression model was significant, with the three variables accounting for 55.5% of the variance in TEGI composite scores. Discussion These findings establish TAP growth as a valid metric of finiteness in the third year of life. Developmental and theoretical implications are discussed.
Journal of Speech Language and Hearing Research 10/2013; · 1.97 Impact Factor
[show abstract][hide abstract] ABSTRACT: Theories of morphosyntactic development must account for between-child differences in morphosyntactic growth rates. This study extends Legate and Yang's (2007) theoretically motivated cross-linguistic approach to determine if variation in properties of parent input accounts for differences in the growth of tense productivity.
Fifteen toddlers (and parents) participated. None were producing tense morphemes productively at 21 months. Two dependent measures of morphosyntactic growth between 21 and 30 months were used: empirical Bayes linear coefficients at 21 months and predicted productivity scores at 30 months. Predictor variables included child sex, vocabulary, and mean length of utterance as well as 4 measures of parent language input at 21 months.
Input informativeness for tense was the most consistent predictor of morphosyntactic growth, explaining 28.3% of the unique variance in children's linear growth coefficients at 21 months and 23.0% of the unique variance in predicted tense productivity scores at 30 months. General input measures were unrelated. Child sex explained an additional 24.7% of the variance in early linear growth. Child vocabulary at 21 months did not explain a significant proportion of unique variance.
The findings provide evidence that input informativeness, an abstract and distributed property of input, contributes to morphosyntactic growth.
Journal of Speech Language and Hearing Research 04/2011; 54(2):549-66. · 1.97 Impact Factor