Interrater Agreement on the Nordoff-Robbins Evaluation Scale I: Client-Therapist Relationship in Musical Activity

Abstract

The purpose of this study was to determine the degree of interrater agreement on an evaluation scale designed by Paul Nordoff and Clive Robbins to track the behavioral responses of autistic children undergoing individual improvisational music therapy and later understood to have application for a wider range of populations. The Client-Therapist Relationship in Musical Activity scale was first published in Nordoff and Robbins’s book Creative Music Therapy in 1977, along with another scale entitled Musical Com- municativeness. Although the scales are widely used, trials involving interobserver agreement have not been undertaken (Wigram, Nygaard, Pedersen, & Bonde, 2002). This study examined the revised version of the first scale, comparing the variance between the ratings of 10 video excerpts of music therapy sessions obtained from a group of certified music therapists (N 1⁄4 34) who have practiced professionally for at least 3 years working with children with developmental delays or autism. Of the 34 participants, 21 had received advanced training and certification in the Nordoff-Robbins (NR) approach to music therapy and 13 had not received this training. The results showed that at a significance level of p < .05, 78 % of the entire group of participants obtained mean scores that were within 1 point of the total group mean, 82 % of the group with NR training obtained mean scores that were within 1 point of the NR group mean, and 74 % of the group without NR training obtained mean scores that were within 1 point of the music therapist group mean. Keywords assessment scales, reliability study, music therapy, Nordoff-Robbins