Re: Q for PhD students?
You’ve asked a very good question and something that Ph.D. students worry about throughout their study tenure. The concept of “original contribution” is rather difficult to grasp… but remember that original is a relative term… your research should be original in the sense that it should be worthy of publication in peer-reviewed journals.
Unlike “Design Research” which is common in the Natural & Physical Sciences, the social sciences are based on tenets of Qualitative and/or Quantitative Empirical Research. A skeleton thesis in the social sciences needs to emphasize the identification of a worthwhile problem or question that hasn’t been previously answered. You’ll probably get thinking about worthwhile research questions once you start doing a formal literature review in your discipline… remember that you’re reading hundreds of journal articles, conference papers, research handbooks and traditional textbooks. Chances are that you’ll develop a liking for a certain subset of problems that you read about and within that subset, there’s a problem that you want to tackle through your thesis.
The original contribution is typically evaluated within the context of the four years that you’ve had research training for. Your evaluators including your supervisor, committee and external examiners will look at your capacity for critical analysis and whether you’re capable of pursuing scholarly research to answer significant questions within a 3 – 4 year time frame.
Also like hskhan said, a lot of times, your Ph.D. may be based on well accepted theoretical models and frameworks and you can extend these to a new context, or in some cases even confirm or disconfirm that theory in a new context. In some cases, depending upon the type of problem you’re tackling, you might even generate a new theory which again adds to the body of knowledge in your discipline.
Ultimately, in the social sciences you’re providing your stakeholders with guidelines, recommendations, best practices, and potential future research opportunities. This is different from Design Research in that the latter may come up with a physical representation / prototype of a system that helps answer the research questions.