PhD students often worry about whether their research will be good enough for a PhD. It's useful to remember the criteria which most universities have at the core of their PhD assessment: 'original work' which makes 'a significant contribution to knowledge'. It is no coincidence that most refereed journals and conferences use similar criteria - such publications are notionally how the research community communicates and continues to build knowledge. Therefore, you can provide evidence of 'significance', 'originality' and 'contribution to knowledge' in advance of submission of your thesis by publishing your work in refereed journals or conferences. There is more on this at various places later in this book. You don't need to make a major discovery to get a PhD - you just need to show that you're able to do good enough research independently.
A number of ingredients are essential for a satisfactory dissertation:
More hangs on the student's ability to demonstrate intellectual maturity and critical depth - and through them to provide insight - than on the scale or scope of the research findings. A good PhD is based on an honest report of research that reflects sound practice and well articulated critical thinking.
Most students, when they hear the phrase ‘significant contribution’, think in terms of a new theory, crucial experiments, technological breakthroughs- the stuff of Nobel Prizes. For a PhD, the truth is that 'significant' need not mean 'revolutionary' or 'major' or even 'large'. The phrase might be more accurately read as 'significant - albeit modest - contribution'.
Characterizing your contribution means answering 'So what?', which means articulating:
Making a 'significant contribution' means 'adding to knowledge' or 'contributing to the discourse' - that is, providing evidence to substantiate a conclusion that's worth making. Research is not something done in isolation; it is a discourse among many researchers, each providing evidence and argument that contributes to knowledge and understanding, each critiquing the available evidence. Research is about the articulation and analysis of phenomena observed and investigated through a variety of techniques. It's about 'making sense' of the world: not just describing it, but also analysing and explaining it. As more evidence is presented, the analysis and explanations are re-evaluated. Knowledge claims can be small and still have a role in the discourse.