Evidence-based medicine and evidence hierarchies have been widely adopted and have strongly influenced decision making across many fields, including clinical aphasiology. However, questions remain about the creation, usefulness, and validity of current evidence hierarchies.

This article builds on ideas about scientific approaches and evidence originally shared by Elman (1995, 1998, 2006). This article reviews the history of evidence hierarchies and argues that improving the diversity of research designs, methods, and perspectives will improve understanding of the numerous and complex variables associated with aphasia intervention. Researchers and clinicians are encouraged to synthesize diverse types of scientific evidence. It is hoped that this article will stimulate thought and foster discussion in order to encourage high-caliber research of all types.

Concepts from a wide variety of fields including philosophy of science, research design and methodology, and precision medicine are brought together in an attempt to focus research on the scientific understanding of aphasia treatment effects.

It is hoped that by incorporating diverse research designs, methods, and perspectives, clinical aphasiologists will become better able to provide effective, personalized treatments, ensuring that each person with aphasia is able to improve their communication ability and quality of life.