These are my notes (or rather verbatim excerpts) from
Chandrasekhar's guide. I am posting this to serve as a quick referral (for me) and for anybody else who does not plan to read the entire original document.
What is a thesis?
Thesis is a proposition to be maintained or proved. It can also be considered as a proposition made as a basis for reasoning without the assumption of its truth. Effectively, a thesis is an (obligatory) offering placed at the desk of the examiner by a candidate who wishes to get a degree. This is the most common, and often only, reason why a thesis is written. But there are other reasons for writing a thesis.
A thesis is a written record of the work that has been undertaken by a candidate. It constitutes objective evidence of the author's knowledge and capabilities in the field of interest and is therefore a fair means to gauge them. Most of all, a thesis is an attempt to communicate. Science begins with curiosity, follows on with experiment and analysis, and leads to findings which are then shared with the larger community of scientists and perhaps even the public. The thesis is therefore not merely a record of technical work, but is also an attempt to communicate it to a larger audience.
Thesis writing : Three S's
A thesis may be analysed into three S's:
Structure confers logical coherence; substance, significance and depth; and style, elegance and appeal. The structure of a thesis is governed by logic and is invariant with respect to subject. The substance varies with subject, and its quality is determined by the technical knowledge and mastery of essentials exhibited by the student. Style has two components: language and layout. The former deals with the usage of English as a medium of sound technical communication; the latter with the physical presentation of the thesis on paper. All three components: structure, substance and style influence one another.
Differences between the undergraduate and postgraduate theses
They share a common structure and need for logical rigour. It is only in the substance and the emphasis placed on it that the differences arise. In general, it is expected that:
- The three most commonly cited qualities to evaluate an undergraduate thesis are originality, independence, and mastery.
- A higher degree thesis is required to present research in the context of existing knowledge. This means a thorough and critical review of the literature, not necessarily limited to the narrow topic of research, but covering the general area.
- A PhD thesis shall be a substantial and original contribution to scholarship, for example, through the discovery of knowledge, the formulation of theories or the innovative re-interpretation of known data and established ideas.
- The PhD candidate should also show clearly what original contributions (s)he has made.
In short, a thesis is evidence of the candidate's capacity to carry out independent research under the guidance of a supervisor, and to analyse and communicate the significant results of that work. The candidate for higher degrees must demonstrate, in addition, mastery of the literature and indicate clearly which is his or her original work, and why it is significant.
Thesis structure
A thesis should conform to the following structure:
- Title page gives the title of the thesis in full, the candidate's names and degrees, a statement of presentation in the form "This thesis is presented for the degree of ...", the department and year of submission.
- Summary or Abstract of approximately 300 words. (It should not exceed 700 words.) The abstract or summary should summarize the appropriate headings, aims, scope and conclusion of the thesis.
- Table of Contents
- Acknowledgements
- Main Text
- Bibliography or References
- Appendices
If we zoomed in on the Main Text, we should see something like this:
- Chapter 1: Introduction
- Chapter 2: Review of the Literature
- Chapter 3: Materials and Methods
- Chapters 4 to n: Experimental Chapters
- Chapter (n + 1): General Discussion or Conclusions
Any of the experimental chapter, should have:
- A brief introduction
- Experimental procedure (methods and materials)
- Results
- Discussion
This structure of an experimental chapter / thesis (in entirety) reflects the time honoured format of science experiments:
- Aim
- Materials and Methods
- Observations
- Results
- Discussion
- Conclusions
Rationale for structure
The rationale for the structure is simply that a thesis must tell a story clearly and convincingly. There is a flow in the logic:
- Introduction/Aim: What did you do and why?
- Materials and Methods: How did you do it?
- Observations/Results: What did you find?
- Discussion: What do your results mean to you and why?
- Conclusions: What new knowledge have you extracted from your experiment?
Any flaw in the reasoning or gap in the logic will be easily spotted if this structure is strictly followed.
The hypothesis underpins the thesis
The hypothesis is all important. It is the foundation of your thesis. It gives coherence and purpose to your thesis. If it is hard to grasp what hypothesis means, these explanations might help:
- The hypothesis defines the aim or objective of an experiment, that if some likely but unproven proposition were indeed true, we would expect to make certain observations or measurements.
- A hypothesis is an imaginative preconception of what might be true in the form of a declaration with verifiable deductive consequences.
- A hypothesis is the obligatory starting point of all experimental reasoning. Without it, no investigation would be possible, and one would learn nothing.
- hypothesis: that which underlies a thesis
Your hypothesis must fit the known facts and be testable. To comply with the first, you must have read the literature. To comply with the second, you must do the experiment. This is why the hypothesis is central to scientifc investigation. If an experiment shows that a hypothesis is incorrect, then that hypothesis must be erroneous, no matter how attractive. Moreover, failure of a hypothesis may lead to a re-examination of assumptions, refutation of shaky theories, and ultimately to new knowledge.
Substance : Begin at the beginning
The content of your thesis is being continuously gathered throughout the period of your project/research. Keep clear, well annotated records. Keep a running record of experiment and observation; be as wordy and repetitive as required. The following could / should be maintained:
- Freehand drawings of experimental setups
- Accurate description of what you believe to be perceiving (no matter however wierd they appear)
- Questions you ask to yourself
Maintain a record book where you record your thoughts, perceptions and measurements, using words, numbers and pictures, as and when they are still fresh in your mind.
Plan your experiments so that one experiment has only one hypothesis. Many experiments may together shed light on a larger, unifying hypothesis.Write with the reader in mind
All communication involves two parties: the sender of the message and the receiver; in written communication, they are the writer and the reader. If you write with the reader in mind you are more likely to communicate successfully. The reader should not waste effort into understanding the substance of the writing, in trying to guess what the writer intended to mean. Some sound generic guidelines are given below:
- Place in the position of importance (stress position) the "new information" you want the reader to emphasize in his or her mind.
- Place the person or thing whose story is being told at the beginning of a sentence in the topic position.
- Place appropriate "old information" in the topic position to provide linkage with what has gone before and context for what is to come later.
- Provide context for your reader before asking him or her to consider anything new.
- Match the emphasis conveyed by the substance with the emphasis anticipated by the reader from the structure.
In summary, lead the reader from the known to the unknown. Write with the reader in mind: this is usually the examiner, but do not forget the poor student who gets to continue your project the next year. If your thesis is not clear enough, (s)he may be condemned to repeat your work before making further progress, losing valuable time in the process.
Think-Plan-Write-Revise
Think. Plan. Write. Revise. Messy thinking leads to messy writing: cluttered, obscure and uninviting. Think and plan before you write and revise. Writing is not a linear process but a cyclic one. What appears first may be written last, with the benefit of hindsight and a unified perspective. But, where does one start; how does one revise, and how many times?
Attikiouzel's aphorisms
- Start writing early: Do not delay writing until you have finished your project/research. Write complete and concise "Technical Reports" as and when you finish each nugget of work. This way, you will remember everything you did and document it accurately, when the work is still fresh in your mind.
- Spot errors early: A well-written "Technical Report" will force you to think about what you have done, before you move on to something else. If anything is amiss, you will detect it at once and can easily correct it, rather than have to revisit the work later, when you may be pressured for time and have lost touch with it.
- Write your thesis from the inside out: Begin with the chapters on your own experimental work. You will develop confidence in writing them because you know your own work better than anyone else. Once you have overcome the initial inertia, move on to the other chapters.
- End with a bang, not a whimper: First and last impressions persist. Arrange your chapters so that your first and last experimental chapters are sound and solid.
- Write the Introduction after writing the Conclusions: The examiner will read the Introduction first, and then the Conclusions, to see if the promises made in the former are indeed fulfilled in the latter. Ensure that your Introduction and Conclusions match 100%.
- "No man is an Island": The critical review of the literature places your work in context. Usually, one third of the PhD thesis is about others' work; two thirds, what you have done yourself. After a thorough and critical literature review, the PhD candidate must be able to identify the major researchers in the field and make a sound proposal for doctoral research.
- Estimate the time to write your thesis and then multiply it by three to get the correct estimate: Writing at one stretch is very demanding and it is all too easy to under-estimate the time required for it.
Others
- The hallmarks of scientific writing are precision, clarity and brevity, in that order.
- Write (your chapters) in four drafts:
- Putting the facts together
- Checking for coherence and fluency of ideas
- Readability
- Editing
- The Introduction should embody the (unified) hypothesis. The reader finds in a clearly expressed hypothesis the skeleton of the thesis. Use flow diagrams, headings, sub-headings etc., to create and sustain interest.
- The scope and emphasis of the Literature Review must be directly relevant to the subject of the thesis. This should be a critical synthesis of the state of the knowledge. Especially important are the areas needing further investigation: what has not been done, as well as what has been done, but for which there is a conflict in the literature. The examiner finds out how the candidate thinks from reading this section.
- Include a common chapter that presents in one place all the experimental details common to all your experimental chapters. This avoids boring repetition and clears the way for a more fluent presentation of experimental results.
- Where several related experiments are grouped into a single chapter, it is preferable to present this sequence individually for each experiment but to conclude with one Discussion. This will meld the experiments together and unify the chapter.
- Materials and Methods Ensure proper quality control and statistical planning and analysis. Retain enough details to allow repetition of experiments for up to seven (7) years, as legally required.
- Examiners ask the following questions when reading a thesis:
- Has the student read all the references?
- What questions does this thesis raise?
- What richness does it contain that can spawn other work?
- What is the quality of flow of ideas?
- Try to present your Results separately from your Discussion. There is a temptation to mingle fact and opinion, but resist it. Your work will be easier to understand if your results (measurements, observations, perceptions) are separated from your discussion (inferences, opinions, even conjectures).
- Use SI units and the preferred abbreviations. Leave a blank space between the number and the SI unit and do not put a full stop after the abbreviation, unless it is at the end of the sentence.
The Experimental Chapters
Each of these should preferably be self contained and clearly focused. Choose and present only those results that are relevant to your hypothesis. A morass of experimental results unilluminated by a hypothesis and unembellished by a discussion is insulting and confusing to your reader.
State your hypothesis clearly. Indicate all assumptions. Include enough information about materials and methods to enable another suitably qualified person to repeat your experiments. Relegate tedious but necessary details to an Appendix, so that there are no breaks in the flow of ideas in your presentation. If you chose some specific conditions for your experiment that may not be readily
apparent to your reader, explain the reasons for your choice here.
It is customary to describe your Methods before the Materials. Describe your algorithm before giving details about the dataset on which you developed and tested it. If you are using a method that has already been documented in the literature, do not describe it in full; describe it briefly or not at all, and give a reference citation.
If your results convey no sense of the new or the unexpected, you must ask yourself whether they are the right results to present, and also whether your hypothesis was well framed in the first place. Do not present results chronologically; present them logically.
Adopt a standard nomenclature for all your chapters and introduce this in one place, preferably in a chapter preceding your experimental work. Do not change your symbols and their meanings as you go along.
Importance of discussion section
The Discussion section of your experimental chapter is where you add value to your work. This is where you comment on your results.
- Why are they what they are?
- What meaning can you wrest from them?
- Are they in accord with accepted theory?
- What do they mean with respect to your hypothesis?
- Do your results uphold your assumptions?
- How do you treat unexpected or inconsistent results? Can you account for them?
- Do your results suggest that you need to revise your experiments or repeat them?
- Do they indicate a revised hypothesis?
- What are the limitations in your methodology?
- How do your results fit in with the work of others in the field?
- What additional work can you suggest?
Throughout your thesis, and especially in your experimental chapters, there should be no gaps in the flow of logic. Keep the links of a chain in mind. Each link is connected to two other links: one before and one after. Absence of any one link is a weakness. Absence of both means there is no chain.
The Literature Review
The literature review is the backdrop on which you present your work. It must be selective, but substantial enough for the merits of your work to be judged in relation to what is known. It is especially critical for a PhD thesis where the claim of originality should be defended with a thorough and critical review of the literature, especially in your specific area of research. You should capture the essence of current knowledge and comment critically on where the interesting questions and inconsistencies lie. The literature review is vital to justify your hypothesis, which must be consistent with what is known.
The Introduction and Conclusions
The Introduction is where you "soft launch" your reader on the work described in your thesis.
Lead the reader from the known to the unknown. State the hypothesis clearly. Give a preview of your thesis, globally and chapter by chapter. Your Introduction has done its work if you have captured the reader's curiosity and interest in this first chapter.
The Conclusions record the power of your scientific thinking. You have to unite all that has gone before with a thread of unified perspective. This is where you say why you think your story is a good one and present evidence from your work to support your claim. The fate of your hypothesis is revealed here: did it stand, fall, or require modification?
You may briefly compare your work with that of others, present whatever new knowledge has been gained from your work, and suggest what may be done to further new knowledge. The Conclusions should give a sense of fulfilment and finality to your thesis.Write the Introduction after you have written the Conclusions and make sure the two match.
Linking your chapters While you are writing your thesis, you might suddenly remember that an idea in Chapter 3 needs to be linked to an idea in Chapter 5, etc. This is a healthy sign because it means that you are integrating your work and seeing your thesis as one whole in your mind. These forward and backward linkages give continuity to your thesis.
The Summary or Abstract
The Summary or Abstract is perhaps the most difficult part to write. Do not make the mistake of trying to write it first: you will waste time and get discouraged. The Abstract should be written last.
I have found the following exercise very helpful in trying to focus the mind on what the point of a thesis (or paper or article) is. Try condensing your thesis in:
- one word
- one line
- one sentence
- one paragraph
- one page
- one chapter
This method is somewhat like asking a dying man for a message: he will tell you only the most important thing(s). You begin at the most "compressed" level of describing your thesis and successively relax the constraint on the number of words to achieve increasing levels of detail. Somewhere along the way, you should have written your one to two page abstract, summarising your thesis adequately.
Writing other parts of your thesis
The Title should be neither too long nor too short. It should be focused and interesting. It should include the keywords you might use to describe your work in a scientific paper or thesis abstracting system. Try to use some verbs rather than a long list of nouns.
The Acknowledgements should include sources of financial support and all those whose help you have sought and got, and all those whose work you have directly built upon.
The Bibliography should only contain references you have actually read. To quote an unread paper is misleading and dangerous. In engineering theses, references are usually cited by number, in order of citation.
Sometimes, it may be necessary to digress from your main story to explain something, especially for completeness. For example, it may be some experimental details, an analytical method, a program listing, etc., that is not central to your story, but whose exclusion would make your thesis incomplete. Include such material in an Appendix. Moreover, do not parrot textbook material in an Appendix just to give your thesis length or to impress your examiners. In all likelihood, they would ignore such material.
Polishing up your thesis
As and when each chapter is written, read it for understanding, paying attention to the flow of logic and sense of continuity. Then read it again, paying attention this time to how comprehensible it is. Finally, read it once more paying attention to spelling, grammar, typography, placement of illustrations, etc. In these three stages, you are evaluating the chapter for its structure, substance and style.
At each reading, revise your thesis as you feel appropriate. When all the chapters are in place, read the thesis again, paying attention this time to overall understanding, coherence, comprehensibility and presentation. Get your supervisor, and anyone else whom you can approach, to read and criticize the early drafts of your thesis.
The time element
It is very easy to underestimate the time needed to plan, write and revise your thesis. As a general guideline, allow one to three months for writing up an undergraduate thesis and at least six months for a PhD thesis. As another rule of thumb, triple your initial estimate to arrive at a more realistic time frame. The period when you are writing up is the period when you are most vulnerable: the excitement of the research is now behind you, your scholarship would be running out or might already have, financial pressures will intensify, and there may be an obligation to work part-time and write up part-time. There may also be attractive job offers vying for your attention. Do not lose motivation during this difficult period. Loss of motivation is one of the principal ways in which you can deprive yourself of your PhD. Write up your thesis and get on with the rest of your life!
