Event- and interval-based measurement of stuttering: a review

Background Event‐ and interval‐based measurements are two different ways of computing frequency of stuttering. Interval‐based methodology emerged as an alternative measure to overcome problems associated with reproducibility in the event‐based methodology. No review has been made to study the effect of methodological factors in interval‐based absolute reliability data or to compute the agreement between the two methodologies in terms of inter‐judge, intra‐judge and accuracy (i.e., correspondence between raters’ scores and an established criterion). Aims To provide a review related to reproducibility of event‐based and time‐interval measurement, and to verify the effect of methodological factors (training, experience, interval duration, sample presentation order and judgment conditions) on agreement of time‐interval measurement; in addition, to determine if it is possible to quantify the agreement between the two methodologies Methods & Procedures The first two authors searched for articles on ERIC, MEDLINE, PubMed, B‐on, CENTRAL and Dissertation s during January–February 2013 and retrieved 495 articles. Forty‐eight articles were selected for review. Content tables were constructed with the main findings. Main Contribution Articles related to event‐based measurements revealed values of inter‐ and intra‐judge greater than 0.70 and agreement percentages beyond 80%. The articles related to time‐interval measures revealed that, in general, judges with more experience with stuttering presented significantly higher levels of intra‐ and inter‐judge agreement. Inter‐ and intra‐judge values were beyond the references for high reproducibility values for both methodologies. Accuracy (regarding the closeness of raters’ judgements with an established criterion), intra‐ and inter‐judge agreement were higher for trained groups when compared with non‐trained groups. Sample presentation order and audio/video conditions did not result in differences in inter‐ or intra‐judge results. A duration of 5 s for an interval appears to be an acceptable agreement. Explanation for high reproducibility values as well as parameter choice to report those data are discussed. Conclusions & Implications Both interval‐ and event‐based methodologies used trained or experienced judges for inter‐ and intra‐judge determination and data were beyond the references for good reproducibility values. Inter‐ and intra‐judge values were reported in different metric scales among event‐ and interval‐based