Purpose: Percentage of syllables stuttered (%SS) and severity rating (SR) scales are measures in common use to quantify stuttering severity and its changes during basic and clinical research conditions. However, their reliability has not been assessed with indices measuring both relative and absolute reliability. This study was designed to provide…

Purpose: Researchers have used unscheduled telephone calls for many years during clinical trials to measure adult stuttering severity before and after treatment. Because variability is a hallmark of stuttering severity with adults, it is questionable whether an unscheduled telephone call is truly representative of their everyday speech. Method:…

Purpose: Stuttering varies between and within speaking situations. In this study, the authors used statistical process control charts with 10 case studies to investigate variability of stuttering frequency. Method: Participants were 10 adults who stutter. The authors counted the percentage of syllables stuttered (%SS) for segments of their speech…

Background: At present, percent syllables stuttered (%SS) is the gold standard outcome measure for behavioural stuttering treatment research. However, ordinal severity rating (SR) procedures have some inherent advantages over that method. Aims: To establish the relationship between Clinician %SS, Clinician SR and self-reported Speaker SR. To…