The degree of Doctor of Philosophy is granted at the University of California not only for the fulfillment of technical requirements, such as residence and the completion of fundamental courses within a given field which is chosen as the field of study, but also upon the following:
- the student's general grasp of the subject matter of a large field of study
- distinguished attainments in that field
- the critical ability and power to analyze problems, as well as to coordinate and correlate the data from a number of allied fields in such fashion as to serve the progress of ideas in those fields
In addition to all of these things, the student must show the power to make an original contribution to the knowledge of their chosen field through the dissertation, and, to give evidence of the ability to work independently throughout their entire career as a graduate student.
The professional doctor's degree represents a mastery of the subject matter and techniques of a professional field to a stage of competence parallel to that required for the PhD. Although the work for the professional doctor's degree may extend the boundaries of knowledge in the field, it is directed primarily towards distinguished practical performance.