Abstract
Fidelity to intervention protocol is linked to best outcomes for individuals with autism spectrum disorder (ASD; see Boyd & Corley [Autism 5(4):430–441, 2001]; Pellecchia et al. [J Autism Dev Disord 45(9):2917–2927, 2015]); however, fidelity measurement tools that are both accurate and feasible for community use are often not available. In this paper we explore methods for validated simplification of fidelity assessment procedures toward the goal of increased use in clinical practice. Video recordings (n = 36) of therapists working with children with ASD were coded using three variations of fidelity assessment methodology (trial-by-trial, 5-point Likert Scale, and 3-point Likert Scale), and the results were compared for exact agreement, mastery criterion agreement, and overall reliability. The results indicated overall a very high percentage of exact agreement (mean 99.44%, range 94.4–100%) and excellent reliability (mean Krippendorff’s alpha [Kα] 1.0) between the trial-by-trial and 5-point Likert Scale across all components; however, the 3-point method may be viewed as being the more feasible strategy within community programs.