This discussion on language log about the word gap based on SES brought to mind early work I did on dynamic assessment of word learning (Peña, Quinn, & Iglesias, 1992; Peña, Iglesias, & Lidz, 2001). The word gap issue focuses on the differences between low and high SES children in the number of words that they hear. The number of words they hear is related to the number of words they know. In our work on DA, my co-authors and I were not interested so much in how low SES children stacked up in terms of number of words they knew (indexed by a standardized expressive single word test) but in their word-learning abilities.In these studies we studied word learning in Head Start preschool-age children. We used the Expressive One-Word Picture Vocabulary Test as pre- and post-test measures. We developed a 2-session intervention using principles of Feuerstein’s mediated learning experience. Our focus here was to teach principles of word-learning and to observe differential performance of children with and without language impairment. I’ve talked about this study before on this blog. Here– I want to focus on the typically developing children because I think the results shed some light on the word gap.
In our studies the Head Start children (who were by definition from poverty backgrounds) as a group scored about 2 standard deviations on the EOWPVT. This is a HUGE gap. Only about 2-3% of the population scores below this range on any given measure. Here, the group mean was about 2 standard deviations below the gap which means HALF of the children we tested were falling in this range. We tested about 6 classes in two schools over two years and this result was pretty stable between years (even with the newer version of the EOWPVT in the second year).
I think that there were a number of reasons for this gap. Cultural and linguistic differences that affect how children responded to test tasks were likely a factor. These affected how children responded to items. Some children were bilingual. We encouraged them to respond in Spanish or English and we used conceptual scoring. Some children didn’t have the home language experiences that would expose them to the words on the test. Certainly, the word gap issue (as described by Hart & Risley) was a factor as well. But, could they show evidence of being able to learn. After all, that’s the real question. I don’t believe that low vocabulary in and of itself leads to low achievement or is indicative of low ability.
So, what happened? Well, after the two 30-minute interventions, children were again tested on the EOWPVT. The typically developing children on average demonstrated gains of about 1 standard deviation. This tells me that they had normal word-learning ability and that their initial pre-test scores did not tell the whole story in terms of their knowledge of words.
What caused this significant change? Well, although I’d like to think it was the intervention, I’m sure that’s not the whole story. I think the intervention focused children’s attention to what they should be paying attention to in terms of single words. It’s likely that they had some exposure to the words on the test, but hadn’t lexicalized them in the expected manner. The intervention highlighted these conventional ways of using specific, single-word names. It’s likely that due to this focus they continued to use this approach outside the intervention sessions in the classroom, at home, and in interaction with peers. See also Silverman’s work on this topic.
So, word gap? Probably yes. But, does it mean we need more talking to kids? I don’t think it’s really a matter of more, but a matter of exposing children to different ways of knowing.