Can books be included in literature reviews?

Question

I am still not sure what should be considered as "literature" for inclusion in a literature review and what are not when writing a research proposal. For instance:

A research proposal: 500-1000 words outlining your plans for your PhD Please include a 'literature review’ of works you’ve consulted and where your ‘contribution to new knowledge’ may potentially be made.

Can books be considered as "literature" for inclusion in literature reviews? For instance:

• Michio Kaku. (2011) Physics of the Future: The Inventions That Will -Transform Our Lives. Reprint, Penguin, 2012.

• Carl Sagan. (1995) The Demon-Haunted World: Science as a Candle in the Dark. Reprint, New York: Ballantine Books, 2000.

I googled and found this and it says:

"The Literature" refers to the collection of scholarly writings on a topic. This includes peer-reviewed articles, books, dissertations and conference papers.

It mentions books but does The Literature above mean literature review?

Also, what about online sources/ articles? Are they "literature" for literature reviews? For example:

• https://www.brainpickings.org/2014/01/03/baloney-detection-kit-carl-sagan/

• https://www.theguardian.com/culture/2009/jul/05/can-artists-save-the-world

• http://www.theoryculturesociety.org/elinor-carmi-cookies-meets-eye/

Answer 1

Whereas pretty much everyone recognizes that a literature review needs to be scholarly, people often seem to get confused about whether it is the literature review itself or its source studies that have to be scholarly. Many people argue that both need to be scholarly, but I disagree: whereas the literature review itself needs to be scholarly (that is, you need to do your review with scholarly rigour), I believe it is sometimes quite appropriate to include source studies in your review that might themselves not be scholarly works. So, to directly answer your question, yes, it might sometimes be appropriate to include non-scholarly books as part of the literature that you review in a literature review.

The challenge, though, with including non-scholarly sources is that a lot of them (maybe over 80% of books and magazines, and maybe 99% of web pages, just to make up some numbers) are garbage as far as scholarly usefulness is concerned. So, if you want to include such sources, it is absolutely critical that you carefully evaluate their quality before deciding to incorporate their arguments and conclusions in your literature review. The advantage of peer-reviewed scholarly sources is that some scholars have already done that work for you. If you use practitioner sources, then you have to do that work yourself. And if you don't, then garbage in, garbage out: your resulting literature review will be just as trashy as the sources you included.

Because of this, some scholars refuse to ever include non-scholarly sources in their literature reviews and advice against doing so. However, practitioner sources can sometimes provide excellent insights and data, and are often much more up-to-date and relevant than any available scholarly source. Thus, I think it's worth the trouble. For an excellent example of a scholarly literature review that incorporates many non-scholarly sources, see Elliot, Steve. "Transdisciplinary perspectives on environmental sustainability: a resource base and framework for IT-enabled business transformation." MIS Quarterly 35.1 (2011): 197-236.

For your specific situation, the books you mentioned seem to be written by respectable physicists (I don't know, though, since I'm not a physicist). If so, they should cite their sources for their claims and arguments. These sources that the books cite should be peer-reviewed. So, if you only repeat claims from these books that cite peer-reviewed sources (and in your literature review, you should cite both the book and the book's source), you should be safe. So, if you do that, then you can benefit from including in your literature review the exciting ideas of a popular book written by a serious scholar. However, if the book doesn't cite peer-reviewed sources, then you should question the reliability of its claims.

I talk about these issues in more detail in a working paper I wrote about how to build theory using literature reviews. Caveat: Some of my ideas have changed since I wrote it, but the sections on the Practical Screen and Quality Appraisal are quite relevant to the points I've raised here.

Answer 2

Note carefully the word scholarly in that description. It refers to works whose intended audience is experts in the field, and which either present novel research or interpret existing results in a novel way. Books can fit that description; often they will have been published by an academic publisher and reviewed for academic merit by expert editors or referees, prior to publication. Scholarly books are sometimes called monographs, especially in the sciences.

The books you mentioned by Kaku and Sagan are not scholarly books. They are intended for a non-expert popular audience, and they don't present new research or expand the state of the art. The same goes for the online sources you listed; they are newspaper articles or blog posts intended for a popular audience.

A literature review is how you show that you are familiar with the state of the art. It convinces the reader that they should believe you when you say that your proposed project is feasible, novel, and interesting. You want to show that you are an expert, or are on your way to becoming one. Citing a popular book won't achieve that; it puts you at the same level as any random person interested in science who can read a bestseller list.

Answer 3

A literature review describes what is already known (and what is not known about a particular topic). So, given your research question, your literature review needs to explain to the reader what previous original research (especially empirical work) has concluded on this question and what is still unknown. This previous research will include findings from both books and papers, but will likely be light on blog posts (unless they present an important argument that is not made elsewhere). At the end of the literature review you need to drive home how your work will help to fill the holes in the literature.