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When you conduct your PhD literature review you’ll need to use all of your skills as a research and academic. The more tools you have in your arsenal, the better. 

Something that is particularly challenging is how to actually conduct the literature review. How do you start with a blank slate, select relevant literature and then tease out the most relevant ideas and, crucially, highlight the most relevant gaps? 

By its very nature, such a task is daunting. You’re being asked to confront a huge body of literature and understand it to such a great extent that you’re able to spot the questions that haven’t been asked.

Pat Thompson, on her great PhD writing/advice blog, talks of there being three stages of the PhD literature review and offers a useful framework for navigating each. 

1. Scoping

2. Mapping

3. Focusing

We’ll use this three-part process to drill down into more detail about exactly how to conduct your literature review. 

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Let’s use a hypothetical example to help us illustrate. Imagine you are studying how the shift to online learning during the Covid pandemic impacted PhD student performance. The first question to ask yourself is where you will look for relevant literature. If you were conducting a study during the pandemic itself, you may put more emphasis on blogs, un-refereed online articles, newspaper reports, and grey literature, alongside the academic literature. That’s because the peer-review process is likely still ongoing.
If you were conducting this review after the pandemic, more papers would have worked through peer review, so you could emphasise those more. Similarly, more book chapters would have been made available. You would likely, therefore, prioritise those over online, non peer-reviewed sources.
Once you have decided where you will look, you must now scrape databases, online depositories, Google Scholar, your university library and any other relevant databases for literature is relevant.
It helps to start out by developing a list of search terms and keywords. Remembering back to the funnel analogy from earlier, be sure you don’t just limit your keywords and terms to your particular niche. You want to be casting a fairly wide net, particularly at this early stage.
Make sure to include variants of your search terms. For example, include Covid, Covid-19, and coronavirus.
As you come across articles, chapters, or other sources, you have to make a decision about whether something is relevant and therefore worth saving. You’ll likely find that there are thousands, or perhaps millions of results when you search for popular terms like Covid.
In that case, you must use selection criteria. I prefer to start by working out what the seminal texts are in the field and who the most important authors are. You can typically find these by referring to:
1. Textbooks
2. Review articles
3. Most-cited articles
Your job at this stage isn’t to read through everything you find. Your job here is to make a decision on relevancy, and then save an article or book chapter. As you save it, you must do so in a way that allows for easy retrieval. Most people prefer to use referencing software, and I encourage you strongly to follow suit. I personally use Zotero, as it’s free and cloud-based. All the major referencing software allows for you to save your literature according to various categories or themes, which makes for easy retrieval.
How you categorise and theme your literature at this stage is a personal choice. It may be that you group it according to what discipline it stems. Or, you may group things into decades or years if you’re conducting a more chronological review. You may have a pre-defined series of categories if you’re conducting a systematic review.
You continue to work in this way – scoping the literature out – until you have a (virtual) pile of things to read. When to move on to reading is down to you. In many ways you never really stop scoping, as you’ll always be coming across new literature as you read and digest articles and books (in a process known as snowball sampling.


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This is the stage of the literature review where you start to digest the virtual pile of readings you collected as you scoped out the literature. This is the most difficult stage, but also the most personal. Everyone will have different ways of reading and digesting the material, and different ways of taking notes as they do so.
Your first job as you map the literature is to filter out what isn’t relevant. This can usually be achieved with a quick scan of the abstract. Discard anything that is obviously unrelated. Keep anything that is even perhaps only tentatively relevant.
In reality, at this stage, you might only read through a small number of complete articles and book chapters. Instead, you’ll find that you’re skimming, trying to ascertain if something is relevant. It’s fine to skim at this stage – when you have really narrowed down the relevant literature, that’s when you read things in much more detail.
You need to find a way to filter through the articles or books that are relevant. For example, scan the abstracts, introduction, keywords, titles and references.
Filter the sources you come across into three separate categories:
1. Must read
2. May read
3. Probably won’t read
As you skim, and later as you read in more depth, you’ll need to summarise the most important and relevant points. There is an art to this, as often you don’t realise why something is relevant until long after you have read it.
For that reason, I find it useful to take standardised notes. I’ve put together a note-taking template that you can use, which you can download by clicking here. You’ll see that there is space for your notes, but also a section asking you to explain how you think what you are reading is relevant.
As you read more and begin to take more and more notes, you’ll start to unpack themes that are emerging across the literature. Your job at this stage is to find out the key debates in the field. 
1. Who is making the most significant contribution?
2. What are they saying?
3. How are they saying it?
4. What aren’t they saying?
As you do so, you’ll begin to see what the key debates are in your field. There might be a number of ’schools’, for example. When you become aware of them, start to focus your literature review around them.
Your list of themes will evolve over time as you read more, but once you have a fairly stable set of themes, it is time to add more literature into each, perhaps broadening the scope of your search within and around each one.
Over time, you’ll be able to categorise literature more easily, even across disciplines, and start to be able to see what the broad discussions, debates and ideas are. In other words, you’ll start providing the academic context. When you read, you must do so critically (a skill we’ll touch on later in the course), which means asking what the weaknesses are and where particular articles or book could be improved.
In order to tease out your own specific research topic, you need to think of the questions that haven’t been asked.


As you work through these three stages you will, over time, start to understand where the problems are, what the shortfalls are, and what questions are yet to be asked.
In other words, you’ll be coming closer to finding the ‘gap’. 
But this takes time, and you’ll have to be patient with yourself. 
We’ve written a number of other guides that will help you as you write your PhD literature review. You can check them out on The PhD Knowledge Base. If you want a crash course on how to structure your thesis, you can check out our 5-star rated How to Write A PhD online course. Or, if you need more hands on support, book a one-on-one PhD coaching appointment today.