Usability of the Language Test for Multilingual Children (LITMUS_NL)

Abstract

Background: There is a lack of suitable language tests for multilingual children to distinguish a developmental language disorder from a language delay, caused by insufficient input in the second language. Therefore, the Language Impairment Testing in Multilingual Settings (LITMUS) test has been developed and adapted into an online version. To implement the Dutch version, LITMUS_NL, the test must be user-friendly and valuable for speech and language therapists. Therefore, the usability needs to be investigated. Aim: To investigate the degree of usability, usability issues, added value, clinical first impression and duration of the digital version of LITMUS_NL for identifying developmental language disorders in multilingual children. Method: This study was a descriptive usability study. The sample consisted of speech and language therapists working with multilingual children in speech and language therapy practices or speech hearing centres. The degree of usability was measured with the system usability scale. Secondary parameters were usability issues, measured with a think-aloud protocol, added value, clinical first impression and time to complete LITMUS_NL, measured with an online-questionnaire. Results: The 24 participants assessed the degree of usability as good, with a mean score of 72/100. 337 usability issues were found in the categories of ‘Instructions’, ‘Technical’, ‘Pronunciation of items’, ‘Spelling errors’, and ‘Development of tests’. The added value was rated 5.60/7. The mean duration was 45 minutes and all domains of clinical first impression were scored 7/10 or higher. Conclusion: This evaluation of usability of LITMUS_NL found a good degree of usability and a positive clinical first impression. A range of usability issues was identified; technical issues that can be solved, but also issues related to the construct of the test which are difficult to adapt. Recommendations: We recommend adapting LITMUS_NL to the feedback of the users and to investigate the usability of LITMUS_NL in daily clinical practice.