Dose × Dose Frequency (Storkel et al., 2019)

Purpose: The goal was to determine whether interactive book reading outcomes for children with developmental language disorder (DLD) were affected by manipulation of dose (i.e., the number of exposures to the target word during a book reading session) and dose frequency (i.e., the number of repeated book reading sessions) and whether pretreatment factors predicted treatment response variation.
Method: Thirty-four kindergarten children with DLD (aged 5;0–6;2 [years;months]) were taught 1 set of words using the Dose 6 and Dose Frequency 6 format from a prior study (Storkel, Voelmle, et al., 2017) and taught a different set of words using an alternative format, either Dose 4 × Dose Frequency 9 or Dose 9 × Dose Frequency 4, determined through random assignment. Word learning was tracked for each treatment via a definition task prior to, during, and after treatment.
Results: Results showed that children with DLD learned a significant number of words during treatment regardless of the dose and dose frequency format but that significant forgetting of newly learned words occurred in all formats once treatment was withdrawn. Individual differences in word learning were related to Clinical Evaluation of Language Fundamentals Core Language and Understanding Spoken Paragraphs scores.
Conclusion: When administered at an adequate intensity, variation in the dose and dose frequency of interactive book reading does not appear to influence word learning by children with DLD. Although interactive book reading continues to show promise as an effective word learning intervention for children with DLD, further development is needed to enhance the effectiveness of this treatment approach.

Supplemental Material S1. Nesting of children within classrooms (identified by teacher) within schools.

Supplemental Material S2. Demographic characteristics of children across the four treatment arms.

Supplemental Material S3. Percentile scores on clinical tests and the percentage of children scoring at or below the 10th percentile in each of the four treatment arms.

Supplemental Material S4. Treatment scripts for each treatment condition and each word set.

Supplemental Material S5. Qualifications of treatment providers for each child for each treatment and qualifications of pre-/posttreatment tester.

Supplemental Material S6. Delay (in days) between children’s last treatment session and immediate or 2-week posttreatment tests for each of the four treatment arms.

Supplemental Material S7. Testing script for definition tests administered pre-, immediate post-, and 2-week posttreatment.

Supplemental Material S8. Parameter estimates for the final piecewise growth model for Set 1 and Set 2 words.

Supplemental Material S9. Percent of children who defined the target word correctly at the final treatment session or immediate posttreatment test relative to characteristics of the word or the exposure context.

Supplemental Material S10. Correlations between the percent of children who defined the target word correctly at the final treatment session or the immediate posttreatment test and various target word or exposure characteristics.

Storkel, H. L., Komesidou, R., Pezold, M. J., Pitt, A. R., Fleming, K. J., & Romine, R. S. (2019). The impact of dose and dose frequency on word learning by kindergarten children with developmental language disorder during interactive book reading. Language, Speech, and Hearing Services in Schools, 50, 518–539. https://doi.org/10.1044/2019_LSHSS-VOIA-18-0131

Publisher Note: This article is part of the Forum: Vocabulary Across the School Grades.