"How long should my literature review be?"
"How many references should my literature review include?"
"How much should I write about each source?"
These are very common questions because there are no clear or consistent guidelines on exactly how much you need to put into your literature review.
But the fact that there are no clear guidelines tells you something about the nature of literature reviews. It tells you that these are the wrong questions to ask and that if you want to write a good review, the length might not be the most important thing.
Dilution vs distillation
Sometimes, adding more content (to any chapter of your thesis) can make it weaker. By adding references just to bulk out the chapter, whether or not you have anything interesting to say about them, you can end up diluting the good stuff.
But if you stick to the things you know about and deliberately exclude sub-standard or irrelevant literature, the review will usually be much stronger.
Remember that your examiner has to spend their valuable time reading your work. They will only wish it was longer if it's well-written and interesting.
Some better questions
So instead of asking how long a literature review should be, or how many references it should contain, it's better to ask the following;
- How do I select the best and most relevant literature?
- How do I structure the literature into a compelling narrative?
- How can I balance the need for detail with the need for breadth?
These questions aren't easy to answer, but they focus your mind on the important problems.