2018 Sat Poster 6659

Saturday, November 3, 2018 | Poster Session II, Metcalf Small | 3:15pm

The validity of a parental-report measure for grammar assessment: acquisition of verb and noun forms in Czech
Š. Matějka, F. Smolík

Parent reports have become widely used as tools for studying language acquisition (e.g. Fenson et al., 1993, 2006). The primary area of use is vocabulary acquisition, but some aspects of grammar have been examined as well. The objective of our study was to evaluate the use of parent reports for studying the acquisition of function words and grammatical morphemes in a morphologically rich language, Czech. This included estimating the validity of detailed parent reports as measures of grammatical development.

The study examined the use of inflected verb and noun forms. Czech verbs are marked for three persons in singular and plural, separately for each tense (plus 3 imperative forms); nouns are inflected for seven cases in singular and plural, though there is a high number of homonymous forms. Parent-report data were collected through two web-based questionnaires. Noun forms were reported for a total of 117 children, and verb forms for 94 children, with children’s approximately equally distributed between 18 and 48 months.

The relative difficulty of verb and noun morphemes was estimated by fitting binomial mixed models in which the presence of a particular morpheme in a particular child was the dependent variable, and the age was the fixed-effect predictor. The effects of morphemes were estimated as random effects, which then served as estimates of relative morpheme difficulty. In addition to morpheme differences, effects of various demographic factors were examined, including child’s gender, birth order, and parental education.

The results revealed that the relative ordering of morphemes by random effects corresponded to the expected difficulty. Contrary to many studies (e.g. Bleses et al., 2008; Arriaga at al., 1998), these demographic factors had no effects on the acquisition of morphemes. In order to examine the validity of parent reports on morpheme production, we compared the data from questionnaires with the frequency of morpheme in transcripts of spontaneous mother-child conversations in children’s homes (3 children in the age between 25 and 37 months, 26 recordings) and in lab settings (50 children aged 30 months ± 6 weeks). These transcripts included different children than were assessed by the parental-report questionnaires. We calculated the correlations between random effects estimates of morpheme difficulty based on questionnaires with the morpheme frequency in children’s transcript data. These correlations were very strong, with ρ = 0.9 (p < 0.001) for noun forms and ρ = 0.76 (p < 0.001) for verb forms using the home trancript data, and ρ = 0.85 (p < 0.001) for nouns in the lab data. The relations and the specific ordering of individual forms is shown in the figures on the following page.

The study indicates that parent report is a valid tool for the assessment of acquisition of grammatical words and forms, even when the level of detail involved is not generally viewed as something parents could report reliably. The reports capture the developmental trends observed in transcripts, and may provide a reliable first estimate of grammatical acquisition trends in underexplored languages with complex grammatical morphology.

References

Arriaga, R. I., Fenson, L., Cronan, T., Pethick, S. J. (1998): Scores on the MacArthur Communicative Development Inventory of children from low- and middle-income families. Applied Psycholinguistics, 19, 209–223.

Bleses, D., Vach, W. Slott, M., Wehberg, S., Thomsen, P., Madsen, T. O., Basbøll, H. (2008): The Danish Communicative Developmental Inventories: validity and main developmental trends. Journal of Child Language, 35 (3), 651–669.

Fenson, L., Dale, P. S., Reznick, J. S., Thal, D., Bates, E., Hartung, J. P., Pethick, S., Reilly, J. (1993): MacArthur Communicative Development Inventories: User’s Guide and Technical Manual. San Diego, CA: Singular Publishing Group.

Fenson, L., Marchman, V. A., Thal, D. J., Dale, P. S., Reznick, J. S., Bates, E. (2006): MacArthur Communicative Development Inventories: User’s Guide and Technical Manual (Second edition). Baltimore: Paul H. Brookes Publishing.