The PhD is a research degree. Unlike a Masters or professional degree, it signals to the world that you have accomplished something significant in the domain of research and the creation of new knowledge. That’s not necessarily a better thing to have done than treat a patient or represent a client or even repair a car – bit it is a different kind of thing, and needs to be respected as such.
The PhD dissertation is unique in its emphasis on establishing its continuity with the whole body of research in the subject area, not only past and present research but research yet to come. In practice, this means that the major aspect that distinguishes a PhD dissertation from a Masters’ or DBA – type thesis is the degree to which it succeeds in opening up more interesting researchable questions than it resolves.
Both projects may begin with similar kinds of research questions; but the difference revolves around this distinction:
– the thesis goes on to answer these questions and present the answers;
– the dissertation may answer the questions, or it may fail to find conclusive evidence one way or another; in either case, it presents and uses the answers as the basis for formulating further questions, rather than as statements having value in and of themselves.
The source of this divergence between the thesis model and the dissertation model lies in the degree to which the research question is based in a body of theory about similar kinds of questions, and the degree to which the results are subsequently interpreted in terms of that theory and generalized to a population across which the theory is supposed to apply.
To illustrate: both kinds of studies might start with a similar sort of question, something like “what factors account for cooperating but different organizations deciding to share applications software?”, and both could address this question with a similar study of several cases in which such cooperating organizations did or did not come to the decision to share. For the thesis, it would be sufficient to say that the question is interesting because particular organizations are losing money because their partners won’t share, and it is sufficient to answer the question by studying how some specific decisions were made in particular cases. Results might consist of formulating several recommendations to both parties as to how to improve their communication and understanding of the situation.
For the dissertation, however, it is critical to describe the question as a specific instance of a more general set or sets of questions, perhaps relating to the nature of collaborative decision making among populations of organizations, or the processes by which organizations chose mission-critical technologies, or maybe both. The question is then reinterpreted in terms of the categories employed in the theory. The assessment of the actual relationship between measurements is interesting more for what it would allow us to say about the relationships between the theoretical concepts than for its applicability to the specific situations studied.
