Hoy identified specific linguistic markers for individual dramatists, most notably a highly distinctive pattern of preferences for John Fletcher, and then employed those markers to distinguish the respective contributions of the collaborators.
Hoy's method and results have earned, if not unanimous acclaim, then at least a high level of recognition for usefulness and validity, and his study stands as a major step forward in the development of stylometric techniques of literary analysis.
He published books and journal articles on specific topics in English Renaissance and Restoration drama, as well as a variety of other subjects, from Charlotte Perkins Gilman to Marianne Moore.
Perhaps his most noteworthy single work is his book The Hyacinth Room: An Investigation Into the Nature of Comedy, Tragedy, and Tragicomedy, published in 1964.
He served as the general editor of the Regents Renaissance Drama series, and was a Guggenheim Fellow.