The topic of my first Research Tuesday Blog is (drumroll please): “Total and Conceptual Vocabulary in Spanish–English Bilinguals From 22 to 30 Months: Implications for Assessment.”
To understand the purpose and findings of this article it is beneficial to know the difference between total and conceptual vocabulary.
Total vocabulary is the sum of the words a child knows across two languages.
Conceptual vocabulary gives the child credit for knowing concepts rather than words, and concepts that are represented in both languages are counted only once.
So basically, when looking at a bilingual child’s total vocabulary you would count both the word perro and the word dog. If you were looking at conceptual vocabulary you would only give the child credit for knowing one concept: the furry, four-legged creature in my house which barks and eats kibble is a dog/perro.
The bottom line about this article? The researchers found that when assessing bilingual children, it is most appropriate and beneficial to look at total vocabulary (total vocab FTW!) A clinician is able to look at total vocabulary in a bilingual child by providing the MacArthur Bates Communicative Development Inventory (CDI; Fenson et al.,1993) in English as well as in the family’s home language.
What happened in this research project? Cynthia Core, Erika Hoff, Rosario Rumiche, and Melissa Señor provided families of 47 bilingual families with the CDI and the Inventario del Desarrollo de Habilidades Comunicativas (IDHC; Jackson-Maldonado et al., 2003.) This was a longitudinal study; the children were assessed at 22, 25, and 30 months-of-age. The children were age and socioeconomically matched with 56 monolingual (English-speaking) children who were assessed with only the CDI.
At the initial 22 month trial, all parents completed the Ages and Stages Questionaire (Squires et al., 1999). The parents of monolingual children completed the CDI, and the parents of bilingual children completed both the CDI and IDHC, at the 22, 25, and 30 month session. The CDI and IDHC provide parents with a checklist of words they have heard their child produce and yields raw vocabulary scores based on this checklist. Both tests provide a percentile based on monolingual norms.
Then the researchers ran all sorts of crazy ANOVAs and t-tests and z-ratios which were totally over my head so I skipped ahead to the conclusion.
The Spanish-English bilingual children showed a mean conceptual vocabulary which was significantly lower than their total vocabulary.
Total vocabulary in the bilingual children was not different from the monolingual children at any of the three sessions.
Conceptual vocabulary in the bilingWual children was considerably lower than the monolingual children at the 30 month visit.
Total vocabulary assessment did not identify any more/less at-risk bilingual children than bilingual children. Conceptual vocabulary assessment identified a higher number of bilingual children who appeared to have vocab development in the low-average range.
When one compares a bilingual child’s vocabulary to monolingual norms it underestimates the child’s expressive language and over-identifies at-risk children.
Using the CDI (and the home-language counterpart) clinicians can get a clear picture of a bilingual child’s total vocabulary without being responsible for considering the child’s language experiences, and language dominance, and language overlap, and the “balance” in their bilingualism. Clinicians are able to see clear change using these protocols (which we all love).
The authors caution us to remember to take socioeconomic status and receptive language into account. They also suggest that monolingual testing may be appropriate in the event that a clinician wants to know about English proficiency (or the proficiency of the home language.) They also pointed out that similar studies have been done previously with mixed results. ALSO the researchers did a really nice literature review to give you more background on bilingualism, total and conceptual vocab etc., so please read that if you desire.
Direct Link (you will need your ASHA login): http://jslhr.pubs.asha.org/article.aspx?articleid=1797298&resultClick=1
Cynthia Core, Erika Hoff, Rosario Rumiche, Melissa Señor; Total and Conceptual Vocabulary in Spanish–English Bilinguals From 22 to 30 Months: Implications for Assessment. J Speech Lang Hear Res 2013;56(5):1637-1649. doi: 10.1044/1092-4388(2013/11-0044).
Fenson, L., Dale, P. S., Reznick, J. S., Thal, D., Bates, E., Hartung, J. P., … Reilly, J. S. (1993). The MacArthur Communicative Development Inventories: User’s guide and technical manual. San Diego, CA: Singular.
Jackson-Maldonado, D., Thal, D. J., Fenson, L., Marchman, V., Newton, T., Conboy, B. (2003). El Inventario del Desarrollo de Habilidades Comunicativas: User’s guide and technical manual. Baltimore, MD: Brookes.
Squires, J., Potter, L., Bricker, D. (1999). Ages and Stages Questionnaire: Parent-Completed Child Monitoring System (2nd ed.). Baltimore, MD: Brookes.