Interest in procedural fidelity has grown rapidly since 1981 as evidenced by the growing numbers of research publications across disciplines on this topic. As a result, the past 30 years of research has yielded a variety of procedures to guide research and practice, which we hope translates into better educational practices and services. Despite…

The articles presented in this special issue both advance what is currently known about treatment implementation in research and practice and illuminate what remains unknown. This article provides a commentary selectively linking current findings to prior research to make arguments regarding those facts that are well established and the gaps in…