How many exposures required to learn a new word?

Interactive book reading* helps children learn new words. But does the same strategy, and same amount of instruction, help children with developmental language disorders, too?

In this study, 27 kindergarten children with nonverbal cognition > 16th percentile and language scores < 10th percentile participated in an interactive book reading* therapy program. To examine the effect of program intensity on word learning, the researchers exposed the children to four different therapy amounts. At the low end, the child would receive three instructional opportunities with a word, across four 20–30-minute treatment sessions (12 total exposures). This was the level that others have used to successfully teach new vocabulary to children from low-income households. However, for children with developmental language disorders, this study found that low level of word exposures to be inadequate. Instead, children with language disorders required 36 exposures to new words to learn them. Just how much therapy is this? Here, it was provided via six instructional exposures to the word per session (e.g. definition, synonym, example sentence, in-text), across six therapy sessions (6 x 6 = 36). Note that they tried a higher-intensity level, too, but learning plateaued. So—look at your lesson plans. Is that roughly what you’re providing?

Note also that that these kids, on average, learned just a portion of the words treated. Also, not all responded well—“Children with lower phonological awareness, vocabulary, and/or nonword repetition scores were less likely to respond positively to the treatment.” Thus, aspects of the treatment, other than intensity, will need to be adjusted and examined to maximize the learning benefit.
Now here’s the exciting part—in the supplemental materials that accompany this article, the authors provide highly-detailed treatment protocols. The scripts tell you exactly what books they used, what words they targeted, and how, allowing you to efficiently replicate the treatment!
Storkel, H.L., Voelmle, K., Fierro, V., Flake, K., Fleming, K.K., Romine, R.S. (2016) Interactive Book Reading to Accelerate Word Learning by Kindergarten Children With Specific Language Impairment: Identifying an Adequate Intensity and Variation in Treatment Response. Language, Speech, and Hearing Services in Schools. Advance online publication. doi:10.1044/2016_LSHSS-16-0014.

*Interactive book reading is when an adult reads the text as written, but inserts questions, comments, and other dialogue to teach the text.