Standards of Proof

Abstract

TASH’s historic commitment to advocacy and science has enabled it to be a trusted voice for people with severe disabilities and their families. We review recent developments in the controversy over facilitated communication (FC) in light of major contextual continuities and changes in the past two decades. A series of scholarly reviews of the literature on controlled experiments have established a preponderance of evidence that FC is not reliably an expression from the individual who receives facilitation. Evidence indicates that the facilitator is the usual source of the text. We discuss the standards of proof of efficacy that must apply before an intervention should be endorsed by a national organization that aims to have a major impact on policy and practices. The need for controlled experiments in evaluation interventions is discussed. The central concern in establishing efficacy of a practice is to rule out other plausible explanations for an outcome. The main concern in establishing effectiveness is replication under real-world conditions. The science-based practices movement has been taken up by most of the helping professions contributing to the education and support of people with severe disabilities. The movement aims to identify practices and catalog them in terms of the trustworthiness of the evidence supporting them. The movement has led to establishing standards for determining when an intervention can be said to be efficacious. We urge TASH to join this movement and, in light of a commitment to science-based practices, argue that it should withdraw its stated endorsement of FC, which is not supported by science-based research.