General purpose of the Candidacy Examination
According to the Faculty of Graduate Studies, the doctoral candidacies are designed to determine the preparedness of the candidate "to do research of high quality in their particular fields of study" (Handbook of Supervision and Examination, Sec. 7.1)
This can be interpreted in the generalist's sense of being familiar with the area of Psychology represented by the specialty program or in the specialist's sense of being familiar with the narrow field of the thesis research. Neither of those two extreme positions is both necessary and sufficient to guarantee high quality work. The candidacy should therefore cover some selected areas beyond the student's immediate research area, i.e., the field covered by the specialty program and the student's supervisor.