Elizabeth DePoy is a theorist and researcher who is best known for her work in methods of inquiry and legitimacy theory. Co-authored with Stephen Gilson, DePoy developed Explanatory Legitimacy Theory. Through that lens, DePoy analyzes how population group membership is assigned, is based on political purpose, and is met with formal responses that serve both intentionally and unintentionally to perpetuate segregation, economic status quo, and inter-group tension.

Her work is substantive and has created an important theoretical advancement in disability and diversity studies through the contribution of explanatory legitimacy theory. This frame of reference has served as the basis for her work and has been acknowledged as a new paradigm for disability studies by many scholars in the field.