Structurally, the Doctor of Computer Science differs from the PhD in that the DCS has, as noted above, a three-year duration, with only one year equivalent on the dissertation, while an American Ph.D. normally requires a minimum of four years, with at least three years spent on the dissertation.

There are two active definitions of what comprises a research doctorate or similar in the U.S. The National Center for Education Statistics defines a Doctor's degree-research/scholarship as "A Ph.D. or other doctor's degree that requires advanced work beyond the master's level, including the preparation and defense of a dissertation based on original research, or the planning and execution of an original project demonstrating substantial artistic or scholarly achievement." The awarding institution defines which degrees meet this description themselves. The National Science Foundation defines a research doctorate as "a doctoral degree that (1) requires completion of an original intellectual contribution in the form of a dissertation or an equivalent culminating project (e.g., musical composition) and (2) is not primarily intended as a degree for the practice of a profession." Under this definition, the DCS, which (as noted above) is intended for professionals in the field of computer science, is not recognized by the National Science Foundation as a research doctorate equivalent to a Ph.D. in Computer Science.