Wednesday, May 2, 2018

Two things every Ph.D thesis should contain

I find that too often both of the elements below are missing or are superficial in a thesis. Yet doing them is important training for a student and just plain old good science.

Suggestions for Future Directions
A good research project will raise new questions and challenges.
Most projects do not get as far as the advisor and student would have liked.
The student should write about:
What would do if I had more time?
What should the next Ph.D. student do?
This can be a separate section or chapter at the end of the thesis.

A sober assessment of the strengths and weaknesses of the approach taken and the methods used.
In these current times of hype, the fierce competition for funding and publication in luxury journals mean that many are reluctant to admit any weakness or the value of possible alternatives.
During question time for a colloquium, the speaker was asked, "What are the weaknesses of your approach compared to the alternatives?"
"I can't think of any. It is better in every way."
However, the only way we can improve things is by considering the weaknesses of what we are doing.

Another reason why both of these may be neglected because doing them well is just plain old hard work.

I think these features are equally important in undergraduate and Masters theses as well.

What do you think?
Are there other essentials?


  1. Ross, I completely agree with your list.

    I would add:
    - information on how the reproducibility of the results was established (e.g. error bars, calibration calculations, ...)
    - sufficient detail that future workers could readily reproduce the results
    - thoughtful citations of the relevant literature

    1. Thanks for the helpful comment.
      I agree these are essentials too, and sadly, often not included.

  2. An article in Nature ( Hope it is alright to cite a luxury journal ?)
    What’s the point of the PhD thesis?
    Doctoral courses are slowly being modernized. Now the thesis and viva need to catch up.
    Julie Gould

    Prof Sholls comment on error bars is relevant to the following discussion.

    This is Q&A started by Rens Wouter van der Heijden, Ulm University, probably an electrical engineer? Some interesting replies are there to the points raised by the questioner.

    Long before the advent of modern simulation, many simple experimental work was also done several times and errors , sd, mean, mode and all the distributions would be done with a calculator and be reported. There used to be a simple principle as to what you intend to get in your experiments and what you get actually is going to be different. The advent of once or twice repeated expts being published, even in good journals to please funding bodies and raise one's bibliometric vanity has resulted in not reporting errors, weaknesses, etc They should make reporting errors etc compulsory as software and tools are more readily availabe than what was available to old timers who slogged hard on their calculators to report this.
    Your Q & A answers below in your posting reminds one of a boxing legends proclaimig " I am the greatest and nobody is the latest"
    "What are the weaknesses of your approach compared to the alternatives?"
    "I can't think of any. It is better in every way."

    1. It is fine to cite luxury journals, as long as they are read critically.
      Thanks for the link to the Nature commentary on the Ph.D thesis. It raises interesting questions that need to be discussed.
      I found I disagreed with most of the suggestions for "improving" things.
      That is probably worth a separate post.
      But briefly, I think oral exams have great value. Unfortunately, Australia does not do them. I also think there is great educational value in the traditional thesis. Making it shorter and/or just stapling papers together (as in Europe) I think is undesirable. Even when students have first author papers they don't necessarily write them or understand them. Forcing them to write on their own is good training and a good test.

  3. Oral defence was there in Australian universities. It was discontinued. Was it the cost of conducting or due to the rivalry between academics within the dept which led to discontinuing oral defence ?
    Or was it both ?
    There are have been several incidents reported of rivalry between academics within the dept to settle scores,resulting in acrimonious questions leaving the PhD student in a psychological mess and the students supervisor's BP rising. A PhD thesis was accepted in the first report when sent out for reading and later rejected after the oral defence by the same examiner. The reason. A three page error in the thesis of the student resulted in this. This error was questioned when the PhD student presented
    in his oral defence this aspect in his slide. The question on this was asked by a heavy weight academic in the dept who was at loggerheads with the PhD student's supervisor. The error was not a huge one. However the examiner accepting first and rejecting the thesis after the heavyweight's question was sheer churlish vendetta.

  4. Prof Sholl

    “The aim of science is not to open the door to infinite wisdom but to set a limit to infinite error.” - Bertold Brecht