PhD Theses

A PhD Thesis, or PhD dissertation, as it is sometimes called, has a special function in the academic community. This written piece of text, typically amounting to 150-300 pages (Swales 2004, p. 102), functions as a kind of scholarly qualifying piece of work, through which the author is admitted into the society of academics seen as sharing some sort of common ground in terms of expert knowledge, skills, critical thinking, rigour, and scientific values.

Two main types of PhD theses

Strictly speaking, there are two main types of PhD theses: the monograph format and the article-compilation format. The monograph, which can be seen as the more traditional type, is written as a coherent, synoptic text, whereas the article compilation thesis (sometimes called multiple-manuscript thesis or anthology) features a series of published/publishable papers compiled into a coherent whole, often with designated introductory and concluding chapters (Swales 2004).

In terms of their spread and use, the article-compilation format is predominantly adopted in the hard sciences and engineering, but it does also occur in some disciplines in the social sciences and humanities. The monograph format is arguably the most commonly used in the soft sciences. On the whole, though, there is a lot of variation when it comes to the preferred format in different disciplines.

Thesis structures

When it comes to the structure of a PhD thesis, there is naturally a great deal of variation going on across different disciplines, but one format is at least at the face of it expected to traditionally dominate: a blown-up version of the IMRD format often used in research articles. Click on the link below to see this traditional format.

A traditional structure of PhD theses (click to expand/contract)

Introduction

 

Literature Review/Survey

 

Methods (Materials/Procedures)

 

Results

 

Discussion

 

Conclusions (Implications/Recommendations)

 

Swales (2004, p. 107)




However, as has been pointed out by Swales (2004), the above traditional structure is perhaps not the most widely used. He argues, for example, that one problem with the traditional structure is that it might be problematic to have only a single chapter dealing with results. This, he continues, "produces an unwieldy and out-of-balance monster chapter in the middle of the text" (p. 108).

An alternative structure for a PhD thesis is similar to the article-compilation format mentioned earlier. This format is seemingly more popular in science and engineering disciplines. Click on the link below to see an example of this thesis format.

A complex (article-compilation) structure of PhD theses (click to expand/contract)

Introduction (definitions, justification, aims)

 

Literature Review (sometimes included in the introduction)

 

(General Methods) (optional)

 

IMRD

 

IMRD

 

...

IMRD

 

Conclusions 

 

Swales (2004, p. 108)


A third structure, allegedly mostly used in the humanities and social sciences, but also found other disciplines (Swales 2004), is called the topic-based thesis. According to Bunton, in these types of theses authors "report and discuss their analyses in multiple chapters (ranging from three to seven) with topic-specific titles" (1998, p. 110). Click on the link below for a schematic overview of the topic-specific structure.

A topic-based structure of PhD theses (click to expand/contract)

Introduction

 

(Literature Review)

 

(Theoretical Framework)

Method

 

Topic: Analysis-Discussion

 

Topic: Analysis-Discussion

 

Topic: Analysis-Discussion

 

Conclusions 

 

Swales (2004, p. 109)


For further reading (click to expand/contract)

A number of articles are available which discuss the structure of theses and dissertations in depth, and which propose methods for effective thesis writing. Here are a few examples:

  • Paltridge, B. (2002). Thesis and dissertation writing: An examination of published advice and actual practise. English for Specific Purposes, 21(2), 125-143. [Access via LibHub]
  • Paltridge, B. (1997). Thesis and dissertation writing: Preparing ESL students for research. English for Specific Purposes, 16(1), 61-70. [Access via LibHub]