Assessing sign language comprehension in adults with intellectual disability and deafness

Language comprehension is an essential component of human development that is associated not only with expressive language development and knowledge acquisition, but also with social inclusion, mental health, and quality of life. For deaf and hard-of-hearing adults with intellectual disability, there is a paucity of measures of receptive sign language skills, although these are a prerequisite for individualized planning and evaluation of intervention. Assessments require materials and procedures that are accurate, feasible, and suitable for low levels of functioning. We adapted measures of English-language comprehension in young children - a direct assessment and a caregiver questionnaire - into Austrian Sign Language and to the target group of adults with intellectual disability and used them with a non-preselected sample of 67 deaf and hard-of-hearing adults with intellectual disability living in therapeutic communities specifically for deaf and hard-of-hearing people with multiple disabilities in Austria. Findings for both assessments demonstrate their construct validity, excellent internal consistency, and a large symmetrical distribution over the referential age range. Acceptance by the deaf and hard-of-hearing individuals and the caregivers and time-efficient administration suggest high practicability. We recommend further implementation in clinical practice, albeit with cautious interpretation of the results, and the inclusion of the instruments in research on intellectual disability and deafness.