title: Measurement of stuttering in adults: comparison of stuttering-rate and severity-scaling methods.
abstract: This study investigated the comparative reliability of 2 stuttering measurement tools when used by experienced judges: percentage of syllables stuttered (%SS) and a 9-point severity scale (SEV). The study also investigated the degree to which scores on 1 tool predict scores on the other and the distributions of stuttering when measured by these tools. Twelve experienced judges watched 3-min videotapes of 90 stuttering and 10 nonstuttering participants. Half the judges rated %SS, and half made severity ratings. Results showed very high intrajudge and interjudge agreement for both measures. There was a strong linear correlation between %SS scores and SEV scores. Based on this finding, it seems that the 2 measures can be regarded as largely interchangeable. The exception to this, however, was in cases where there was either a small number of significant fixed postures (blocks and prolongations) or a large number of innocuous repeated movements (repetitions) in the speech sample. In such cases, it appears that %SS and SEV scores combined would be needed to provide a valid measure of stuttering. SEV scores were more normally distributed than %SS scores, which were clearly skewed. The advantages and limitations of the SEV scale are discussed.
authors.affiliation: Australian Stuttering Research Centre, The University of Sydney, Lidcombe, New South Wales, Australia. s.obrian@fhs.usyd.edu.au
authors.forename: Sue
authors.initials: S
authors.lastname: O'Brian
authors.forename: Ann
authors.initials: A
authors.lastname: Packman
authors.forename: Mark
authors.initials: M
authors.lastname: Onslow
authors.forename: Nigel
authors.initials: N
authors.lastname: O'Brian
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013068:Speech Production Measurement / Q000379:methods*; D013342:Stuttering / Q000175:diagnosis*; D014743:Videotape Recording