A Randomized Trial of the Digital Down Syndrome LanguagePlus (DSL+) Vocabulary Intervention Program

Abstract

This study investigated the effect of the digital Down Syndrome LanguagePlus (DSL+) intervention on vocabulary outcomes through a school-delivered randomized controlled trial. A national sample of first graders with Down syndrome from 91 schools was allocated to an intervention group ( n = 50), which received daily intervention for 15 weeks, or a business-as-usual control group ( n = 53). The intervention involved picture book sharing and structured tasks and was organized as one-to-one, small-group, and full-class lessons. Children in the intervention group made greater gains than children in the control group in expressive vocabulary breadth ( d = .429, CI [.160, .699]) and receptive vocabulary breadth ( d = .447, CI [.193, .700]). The outcomes indicate that the novel DSL+ intervention is an effective intervention to increase trained vocabulary among first graders with Down syndrome, and it takes only 15 minutes of effort 5 days a week.

Parent-Implemented Oral Vocabulary Intervention for Children With Down Syndrome

“…We conducted this study to investigate whether parent-implemented oral vocabulary intervention for young children with DS would result in increased scores on mastery measures of targeted vocabulary. This study adds to the small number of previous studies that investigated technology-based oral vocabulary intervention (Rivera et al, 2013, 2017) and is one of few studies to focus on oral vocabulary intervention for children with DS (see Næss et al, 2021; O’Toole et al, 2018). We included four children ages 5 to 6 years, three of whom completed the adapted intervention (five stories, 40 to 57 sessions).…”

“…We made several a priori adaptations to Næss et al’s (2021) procedures to increase (a) our ability to demonstrate a functional relation within single case research, and (b) feasibility for parent implementers. Næss et al included 22 stories in their original investigation and we chose five of these stories that the researchers identified as high-interest.…”

“…Recently, Næss et al (2021) responded to the lack of research on oral vocabulary intervention for children with DS by developing a systematic intervention package—The DSL+. Multiple research-supported components (e.g., picture book dialogues, direct instruction, story repetition, and use of words in different contexts) are included in the intervention.…”

“…To date, Næss et al (2021) have completed one RCT to investigate whether DSL+ increased oral vocabulary usage for children with DS. Participants were a national cohort of 103 Norwegian first graders with DS (ages 5–7 years).…”

Word prediction using closely and moderately related verbs in Down syndrome

“…1 They usually present delayed speech ( Roberts et al, 2005 ) and speech errors ( Rosin, 1988 ). In a longitudinal study, Næss (2022) evaluated children with and without DS with similar non-verbal mental age, auditory memory, oral motor skills, and receptive vocabulary and found a slower growth of expressive vocabulary in people with DS than those with TD. People with DS also experience morphosyntactic difficulties in production: problems with gender and number agreement between articles and nouns ( Eadie et al, 2002 ), and errors in grammatical categories, including verbs, in spontaneous speech ( Chapman et al, 2000 ; Chapman, 2006 ).…”