Reporting negative results/failure of experiments in thesis/papers

Question

During the various sub-projects of my PhD (physics) we encountered several difficulties (as it is common, I assume) both in technical and in physical nature which we had to solve. Moreover, some experiments resulted in bad results or no results at all. Nevertheless, we identified the issues and noted how to avoid those problems (or how to fix them) in the future.

After we spent considerable time investigating and fixing those problems I would like to mention those issues (and the solutions) if not in papers, but at least in my thesis to avoid future readers the same problems, but my supervisor is completely against reporting any negative results. His stance is that any negative result or technical issue would paint me in a bad light (even though we could solve them), and therefore I only should report good results without mentioning problems.

This confused me (why would anyone view me in a negative way if I report problems in my thesis, and how we could circumvent or fix them), and my local colleagues could not give a conclusive answer either. Therefore, are such stances common, and if yes, why?

Answer 1

I agree with you but suggest that you follow your advisor's advice about your dissertation. To a fairly large extent you are limited by the standards of your advisor until you finish your degree. Even when their advice isn't optimal.

Research is a search for truth, not for results. Negative results can be just as important as positive ones in the search for truth and should, in principle, be reported so that, just as you say, others don't follow blind alleys.

But too many people, I think have the opposite view that a negative result is a failure in some sense, even when it contributes to knowledge. Your advisor may be one of these.

But the purpose of the dissertation is to get it approved and get the degree. After that, the standards you follow can be (more or less) your own. So, a tactical retreat here may lead to a strategic victory. Your dissertation won't be your last, nor, hopefully, your best work.

Answer 2

Assuming the difficulties are nontrivial, you are right and your supervisor is wrong. Here's my suggested approach to the situation.

You want to say: We did X using parameter A and found that Q did not work because of theory M. Then we did X using parameter B and found that Q worked.

Your advisor wants to say: We did X using parameter B and found that Q worked.

What you could say: Theory M says that parameter A will cause Q to fail and parameter B will cause Q to succeed. We did X using parameter B and found that Q worked.

This paints your work in a positive light as your advisor wishes. It also informs your reader about what does not work.