How to write a Ph.D. thesis Introduction chapter?

Question

I am in the process of writing my Ph.D. thesis and struggling with the introduction chapter, what to cover, and what not. This is a technical thesis. The broad area is molecular simulation in statistical mechanics.

There are lots of tips available on the Internet, but those are very general often. I have found a few theses also searching on Google. All those tips and theses vary in style and content and it is difficult to decide which one to follow. Please provide tips on how can I write a good introduction chapter with high academic standards.

EDIT: After reading your valuable input, I am adding here a few more points. (Thanks everybody). Your comments on these points are highly appreciated.

1. I have seen theses where people include background theories. On this matter, I have read that the theory should not be something that others know. Now, this is difficult to predict what to include as background theory, and what not. I have seen people include theories that are widely available in textbooks.

2. Chapter 2 is dedicated to the literature review. It is also important to briefly mention the background and relevant research works. Here I have found people are giving a little elaborate technical detail.

Answer 1

My thesis, which does happen to be in the area you are writing about, took a somewhat different approach for the introductory chapter:

• Motivations—why is this particular problem important
• Related efforts—in what context was the work done
• A short summary of the main development of the thesis (without a formal hypothesis statement)
• An outline of the remainder of the thesis

The following chapter, which was also an "introductory" chapter, but more of a "preliminaries" chapter, defines all the major concepts, tools, and ideas used in the remainder of the thesis (which were derived from my published papers, and therefore somewhat briefer than what is needed for a thesis).

Answer 2

I am in a slightly different field to you (atmospheric physics), but have had my PhD thesis approved for submission. Your university should have a style guide available to you - take that advice first.

My introduction comprised the following sections (this was also used successfully for my MSc):

• Rationale - this comprises an overview of the background knowledge in the field (and was expanded on in the Literature Review that was written after the Introduction). Make sure all variables are explained in detail here (dependent, independent and controlled).

• Hypothesis - what exactly is the predicted result of the entire project.

• Objectives - The main outcomes of the research (these related to the main papers that have been written and published along the way).

• Thesis structure - how the thesis is organised.

Answer 3

In my opinion, all the other answers omit a very important purpose of the Introduction: You should introduce not only the thesis but the results of other people in the Introduction.

A good introduction cites quite a handful of works by other people. Basically, a reader, after reading the Introduction, should have a good idea as to what the thesis is going to be about, and in what wider concept of science it fits, and this cannot be done without citing other people. This shows that you are not doing some rubbish that nobody is interested in.

Answer 4

The introduction of a thesis is a good place to give a bird’s eye view of the problem you face, its importance, relevance to major challenges in the field, and possible applications (including in related fields). You can very briefly explain what others have done to approach it, but I would definitely not include there a full review of the literature. You want the introduction to give the readers (and demonstrate to your committee) that you have a high-level understanding of the context and problem at hand.

Then, you can include a section giving a full review of the state of the art in the field (i.e., what others have done so far) later in the manuscript, either as its own chapter or as part of a “methods” chapter that is structured as such:

Methods
    1. Foundations of molecular simulation
    2. State-of-the-art for your specific problem
    3. Methods you have developed

Answer 5

An introduction is a funnel into your work, be it a paper or a thesis. The basic idea is to start by providing the wider scope within which your work resides. You then focus in on your part of the field or research question through a few steps.

The wider perspective of the beginning should also be the perspective in which you will later put your own results, to show how they feed back into some more general perspective. This part should allow the reader to focus in on relevant research and obtain a firm background of the current knowledge in the field. Once you have established the background you should identify for the reader the gap of knowledge which you have tackled. you then finish off by stating your plan for solving the problem so that your choices of methods etc. can be seen from the perspective of knowns and remaining problems to be solved. We can summarize the text as

Background

Gap

Your approach to a solution

Writing a thesis and a paper can mean this approach can be accomplished in several ways. In a research paper, all of this usually goes into a single heading "Introduction". When you write a thesis the introduction may be many pages long and it is not uncommon to either have the list above as subheadings under the introduction or to outline this part slightly differently.

When you have a lengthy introduction, you may start out by having a chapter called introduction, which does what has been outlined above but cuts out the background details and only summarizes what is known and identifies gaps, almost like a summary of the whole introduction. You then follow up with a detailed background in a separate chapter and likewise for identifying gaps and providing the outline of your research.

The point is that there are many ways to format or partition an introduction but the general idea is still there regardless of what form of publication you are writing: research paper or thesis.