An Investigation of the Clinical Use of a Single-Word Procedure to Assess Intelligibility (Swedish Test of Intelligibility for Children) and an Evaluation of the Validity and Reliability of the Intelligibility in Context Scale

Purpose: Intelligibility is a core concept of speech-language pathology, central both to the assessment of speech disorders and to intervention in such disorders. One purpose of this study was to investigate the reliability and usability of a single-word assessment procedure, the Swedish Test of Intelligibility for Children (STI-CH), in a clinical setting. Another purpose was to investigate the validity and reliability of an assessment method designed to assess functional intelligibility: the Intelligibility in Context Scale (ICS). Method: Thirty children aged 4;1-10;1 years;months were recruited from speech-language pathology clinics in Western Sweden. Each child's treating speech-language pathologist served as listener in the STI-CH assessment while the ICS was completed by each child's parents. External listeners (2 last-year speech-language pathology students) were used to assess the validity of the speech-language pathology. Results: The mean duration of the test procedure for the STI-CH was about 19 min, and 57% of the test sessions were reported as difficult. There was a weak but statistically significant correlation between the results from the STI-CH and the ICS (r = 0.40, p < 0.05), and both methods showed high reliability in terms of interlistener reliability (intraclass correlation exceeding 0.97) and internal consistency, respectively. Conclusions: The STI-CH had high reliability and was time efficient but had some procedural problems. The ICS had moderate validity but high reliability. The STI-CH is promising for clinical use but needs to be developed further. The validity of the ICS can be discussed and needs to be further investigated.