Reading intervention for students with intellectual disabilities without functional speech who require augmentative and alternative communication: a multiple single-case design with four randomized baselines.

Background: Literacy is one of the most important skills a students can achieve, as it provides access to information and communication. Unfortunately, literacy skills are not easily acquired, especially for students with intellectual disabilities who require augmentative and alternative communication (AAC). There are many barriers to literacy acquisition, some due to low expectations from parents and teachers and lack of evidence-based reading programs and reading materials adapted for AAC. Barriers as a result of extensive support needs is also a real factor. This trial aims to deliver reading instructions to 40 students with intellectual disabilities who require AAC and contribute in the debate on how to best support this population through reading instructions to maximizes their reading skills.

Methodology: Forty non-verbal or minimally verbal students (age 6-14) with intellectual disabilities who require AAC will be part of a reading intervention with a multiple single-case design with four randomized baselines. The intervention period will last for 18 months and will commence in March 2023. The students will receive the intervention in a one-to-one format, working systematically with a reading material that contains phonological awareness and decoding tasks based on the Accessible Literacy Learning (ALL) developed by Janice Light and David McNaughton. All the teachers will be trained to deliver the reading intervention.

Discussion: The reading material "Lesing for alle" (Reading for all) is based on and follow the strategies behind the research of ALL. The current trial will through a reading intervention contribute to move beyond only teaching sight words and combine several reading components such as sound blending, letter-sound correspondence, phoneme segmentation, shared reading, recognition of sight words, and decoding. The strategies and methods in use is built on the existing science of reading, especially what has been effective in teaching reading for students with intellectual disabilities who require AAC. There is limited generalizability of prior findings in reading-related phonological processing interventions to different populations of them who use AAC specially outside of the USA. More research is needed to understand how programs designed to improve reading skills across other settings understand the program's long-term effects and to study the effectiveness when delivered by educators who are not speech language therapists or researchers.

Trial Registration: NCT05709405 . Registered 23 January 2023.