How to Write a Science Thesis/Dissertation

HomeHow to Write a Science Thesis/Dissertation

A thesis/dissertation is a long, high-level research paper written as the culmination of your academic course. Most university programs require that graduate and postgraduate students demonstrate their ability to perform original research at the thesis/dissertation level as a graduation requirement.

Not all theses/dissertations are structured the same way. In this article, we’ll specifically look at how to structure a thesis/dissertation in the sciences and examine what belongs in each section. Before you begin writing, it is essential to have a good understanding of how to structure your science thesis/dissertation and what elements you must include in it.

How are science theses/dissertations structured?

There isn’t a universal format for a science thesis/dissertation. Each university/institution has its own rules, and these rules can vary further by department and advisor. For this reason, you must start writing/drafting your thesis/dissertation by checking the rules and requirements of your university/institution.

Some universities mandate a minimum word count for a thesis/dissertation, while others provide a maximum. The number of words you are expected to write will also vary depending on the program/course you are a part of. A Master’s level thesis/dissertation can range, for example, from 15,000 to 45,000 words, while a PhD thesis/dissertation can be around 80,000 words.

While your university/institution may have its own specific requirements or guidelines, this article provides a general overview of how a typical thesis/dissertation in the sciences should be structured. For easier understanding, let’s break it up into two parts:

  1. Thesis body
  2. Supplemental information

The thesis body of your thesis/dissertation includes:

  • Title page
  • Acknowledgements
  • Abstract
  • Table of contents
  • Introduction/Literature review
  • Materials/Methodology
  • Results
  • Discussion/Conclusion
  • Figure and tables
  • List of abbreviations
  • Glossary

Your thesis will conclude with the supplemental information section, which comprises:

  • Reference list
  • Appendices

Your thesis may or may not include each and every one of these sections. Now, let’s examine the parts of a thesis/dissertation in greater detail.

The parts of a science thesis/dissertation: Getting started

Let’s begin by reviewing the sections of the thesis body, from the title page to the glossary. This part of your thesis/dissertation should ideally be written last, even though it comes at the beginning. That is because it is the easiest to put it together once you have written the rest of your thesis/dissertation.

Title page

Your thesis/dissertation should have a clear title that sums up the content. In addition, the title page should include your name, the degree of your thesis/dissertation, your department, advisor, and the month/year of submission. Your university/institution likely has its own format for what should be included in the title page, so make sure to check the relevant guidelines.


This section gives you the opportunity to say thanks to anyone who gave you support while you worked on your thesis/dissertation. Many people use this section to give credit to their advisor, editor, or even their parents. If you received any funding for your research or technical assistance, make sure to mention it here.


Your abstract should be a brief summary (generally around 300 words) of your thesis/dissertation. You can think of your abstract as a distillation of your thesis/dissertation as a whole. You need to summarize the scope and objectives, methods, and findings in this section.

Table of contents

 The table of contents is a directory of the various parts of your thesis/dissertation. It should include the headings and subheadings of each section along with the page numbers where those sections can be found.

Figure and tables

 Think of this section as the table of contents for figures and tables in your thesis/dissertation. The titles of each figure/table and the page number where it can be found should be in this list.

List of abbreviations

This list is intended to identify specialized abbreviations used throughout your thesis/dissertation. This can include the names of organizations (WHO, CDC), acronyms (PFC), and so on. For a science thesis/dissertation, it is preferable to also include a note regarding any abbreviations for units of measurement and standard notations for chemical elements, formulae, and chemical abbreviations used.


In this section, you would define any terminology that your target audience may be unfamiliar with.

The parts of a science thesis/dissertation: Presenting your data

Introduction/Literature review

Following the glossary, the thesis body of a science thesis/dissertation begins with the introduction. The introduction section of a science thesis/dissertation often also includes the literature review. This is unlike most social science or humanities theses/dissertations, where the literature review commonly forms a separate chapter. The introduction section should begin by clearly stating the background and context for your research study, followed by your thesis question, objectives, hypothesis, and thesis statement. An example might be: 

“The connection between nicotine consumption and insulin resistance has long been established. However, there is no substantial body of research on how long insulin resistance is maintained after people quit smoking. In this study, we aim to measure levels of insulin resistance in otherwise healthy subjects following a total cessation of nicotine consumption. We hypothesize that insulin resistance will begin to decline rapidly within six months.”

 The introduction should be immediately followed by a review of earlier literature written on the thesis topic. In this section, you should also clearly identify where the literature connects to your study and how your research study fills a gap or bolsters previous studies. Fit your study within the puzzle of previous work and demonstrate the importance of your research.


In the methodology section of your thesis/dissertation, you must explain what you did and how you did it. If you used materials (for example, bacteria), make sure you clearly list each one. Live materials should be listed including the specific strain and genus. You must explain your techniques, materials, and methods such that another researcher can replicate exactly what you have done.


In the results section, you will explain what happened. What were your findings? This section should be heavy on data and light on analysis. Usually, in-depth analysis and interpretation of your results will be covered in the discussion section of your thesis/dissertation. While you should present your results in full, any supplementary data that you don’t have room for can be included in an appendix. As a note, this section is often written in the past tense. While other portions of your thesis/dissertation may use past and present interchangeably depending on the topic at hand, the results section of a scientific paper focuses on what has already happened (in an experiment), which is why it is written this way.


In this part of your thesis/dissertation, you will discuss what your findings mean. Did they align with your hypothesis? If so, how? If not, what was different? If there were any exceptions, errors, or total lack of correlation found, do not try to hide it. Clearly discuss what it might mean, or if you aren’t sure, don’t be afraid to say so. In this section, you can also highlight potential practical applications for your research study, limitations of your study, directions for future studies, and once again highlight the importance of your study in the field. This section usually concludes with an overall summarization of whether your results support your hypothesis or not. For example:

“Our study found that 500 of our 600 subjects continued to exhibit high levels of insulin resistance three years or more after stopping nicotine use. This does not support our hypothesis that insulin resistance would begin to drop around six months after subjects stopped nicotine use. Further research is warranted into the mechanisms by which past nicotine use alters insulin resistance levels in former smokers.”

Reference list

The reference list is an alphabetical or numerical list of sources you’ve used while researching and writing your thesis. The formatting of your reference list will be dependent on your university guidelines. Useful tools like citation generators can help you correctly format your references. Reference managers like EndNote or Mendeley are also helpful for compiling this list. Furthermore, a professional editor or proofreading service can ensure that each reference is correctly formatted.


This section can be very useful if you want to include materials that are relevant to the topic of your thesis/dissertation but which you were unable to include in the main text. Tables, large bodies of text, illustrations, forms used to collect data or perform studies, and other such materials can all be included in an appendix.

Critical steps for planning, drafting, and structuring a science thesis/dissertation

Writing your thesis/dissertation is a daunting and lengthy task. Here are some helpful tips to keep in mind when drafting your science thesis/dissertation:

  1. Choose a thesis topic that is of professional interest to you. You are going to spend a lot of time thinking, reading, and writing about your thesis topic. Many aspiring young researchers end up working in a field related to their thesis/dissertation. If you start researching or writing a proposal and then decide you aren’t into the topic, don’t be afraid to change directions!
  2. Plan your thesis timelines carefully. Is your topic realistic given the time and material constraints you have? Do you need to apply for external funding for your research study? Will that take additional time? Write a schedule and revisit/revise it often throughout your thesis/dissertation process.
  3. Don’t wait until the last minute to start writing! A thesis/dissertation isn’t like an undergraduate paper where you spend some time researching and then some time writing it. You will need to write your thesis/dissertation as you continue your research study. Write as you work in the lab. Write as you learn things and then revise. Ideally, by the time you have finished your actual research study, you will already have a substantive draft.
  4. Start writing the methodology section first. This is often the easiest because it is straightforward and you have already done quite a lot of the work while preparing your research study. The order in which you write your thesis/dissertation doesn’t matter too much—if you find yourself jumping between sections, that is perfectly normal.
  5. Keep a detailed list of your references using a reference manager or similar system, with tags so that you can easily identify the source of your information.

Final tips for writing and structuring a science thesis/dissertation

Writing a thesis/dissertation is a rewarding process. As a final tip for getting through this process successfully, don’t forget to leave sufficient time for editing and proofreading. Your thesis/dissertation will go through many drafts and revisions before it reaches its final form.

Engaging the services of a professional can go a long way in helping you produce a professional and high-quality document worthy of your research. In addition, there are many helpful tools like AI grammar checker tools available online for students and young researchers.

Check out our site for more tips on how to write a good thesis/dissertation, where to find the best thesis editing services, and more about thesis editing and proofreading services.



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