title: Is the reliability of a visual analog scale higher than an ordinal scale? An experiment with the GRBAS scale for the perceptual evaluation of dysphonia.
abstract: Perceptual evaluation of 14 pathological voices was performed by 29 listeners using the GRBAS scale. To evaluate scale effects on the judgments, 2 versions of the scale were presented: the original 4-point scale and a visual analog scale. Each listener used the same voice samples for both versions of the scale with an interval of 2 weeks. Agreement was found to be higher with the original 4-point scale than with the visual analog version for all scale items G, R, B, A and S. Although a visual analog scale seems to enable a finer judgment of voice quality, this study showed that, with increased freedom of judgment, the interrater agreement decreased considerably. Therefore, we recommend the use of the original 4-point version of the GRBAS scale.
authors.affiliation: Department of Otolaryngology, Head and Neck-Surgery, University Hospital, University of Antwerp, Belgium. wuyts@uia.ua.ac.be
authors.forename: F L
authors.initials: FL
authors.lastname: Wuyts
authors.forename: M S
authors.initials: MS
authors.lastname: De Bodt
authors.forename: P H
authors.initials: PH
authors.lastname: Van de Heyning
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010036:Otolaryngology / Q000379:methods; D010700:Phonetics; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013067:Speech Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D014832:Voice Disorders / Q000175:diagnosis*