What is a Literature Review?

What’s a Literature Review?

The straightforward answer is that a literature review is a review or synthesis of all the research published on a certain topic. But I’d rather explain it from a skateboarder’s perspective:

One of my favorite movies is the 1989 classic Back to the Future Part 2 where the bodacious skater Marty McFly time-travels to the future and sees a hoverboard. As a kid, I was a dabbling skateboarder and thought if I could just have one of those hoverboards, all my troubles would disappear. It was an optimistic time.

Trouble is, hoverboards are really hard to make. We’ve already passed the year 2015 when the “Future” of Back to the Future Part 2 takes place, and guess what? No hoverboards. I know you’ve seen a skateboard-like, two-wheeled device marketed with the name “Hoverboard” but that’s just an electric, no-handled scooter.

I want a real hoverboard. That you ride in the air. So how can we know when real hoverboards will be available? How can we know where the technology is now? Will we know a real hoverboard when we see one? Tony Hawk, the best skateboarder of all time (whose face was incidentally taped to my wall in the ’80s) recently filmed a 2-minute video of how far real hoverboard technology has come–filmed on the very day Marty McFly supposedly went to the future: October 21, 2015:

Tony Hawk and the cutting edge of hoverboard research

Watch on YouTube

Although this “hoverboard” was really a huge black rectangle the size of Delaware floating only an inch off the ground, and although Tony Hawk fell off a lot, he was technically in the air, so I’m taking that as a good sign. Then recently, a professional jet ski rider broke the world record for longest time “hovering” in the air with a highly dangerous jet-engine-propelled contraption called Flyboard Air. It’s also definitely a step in the right direction, but there’s a big problem (beside extreme danger): it’s projected to cost around $250,000.

The good news is, now we’ve found the point where hoverboard research actually is. The bad news: we have to face the sad truth that it might still be a while before we get real flying hoverboards. But at least now we know.

The State of a Field on a Topic

That leads me to literature reviews. Whenever you want to know the state of a field of research like how far hoverboard technology has come, the best way to find out is probably not YouTube videos. It turns out you can do something much more reliable: conduct a literature review. In this case, “literature” doesn’t mean the Victorian novels you read in English class, it means all the research published on a certain topic. So a literature review is simply a review or a synthesis of the research published on a topic.

Researchers today don’t just start projects out of the blue–they do their homework first by finding out what others have already researched. So if you want to make a hoverboard, you don’t just go to Home Depot and buy random parts–you research what others have done and check out the conversation so you don’t have to reinvent the wheel.

“If I have seen further, it is by standing on the shoulders of giants.” –Sir Isaac Newton (and the motto of Google Scholar)

Before good researchers set up any surveys or experiments, or even write a proposal for funding, they figure out exactly which research questions have already been asked and answered. Same goes for anyone wanting to make a product that will sell. But more importantly, they look for the gaps in the research where answers have yet to be found. And then they focus their own research on filling in some of those gaps. That’ll be your job, too.

In other words, the goal of a literature review is to find the sweet spot where the most promising research is happening now–we call that the cutting edge.

How is a Literature Review different from a typical Research Paper?

You’ve probably been writing research papers most of your life– starting from the five-paragraph essay you learned in high school to the term paper you wrote last semester that had a thesis statement and lots of quotes. So it can seem daunting to switch gears to writing a literature review, but there are some distinct advantages to making the switch. The trick is first understanding the difference between the two.

Research Papers are Thesis Driven

The difference between a typical research paper and a literature review is your purpose and strategy. When you’re assigned to write a research paper, you start with a thesis or argument that you’d like to make. Your thesis has to do with changes you’d like to see in the future. Then you search for sources that support your point. You might adjust your thesis if you come across sources that challenge your claim, but generally, the sources you’ve gathered become evidence for your thesis and you use them to support your point. In other words, your argumentative research paper is driven by your thesis.

Literature Reviews are Source Driven

In contrast, when you write a Literature Review, the sources themselves dictate what you’ll say in your paper. Remember, your goal is to tell your audience the state of the field on a topic–what’s been happening in the published research–so you can find the cutting edge and where the research gaps are. Therefore, you need to find and evaluate the most relevant sources surrounding a topic and then write a review based on what you find. You can’t decide on a thesis statement or know what points you’ll make before you start because you have to find out what researchers are doing before you can report on that. Simply put, your literature review is driven by your sources.

You’ll still have an overarching point/thesis that controls your literature review paper structure, but it will be a claim about what patterns you found in the research–not an argument about a change you want to see in the future or a new way to look at something. And you’ll decide on your thesis much later in the writing process. Here’s a table that compares the writing process of a traditional research paper with that of a literature review:

	Traditional Research Paper	Literature Review
	Thesis-driven	Source-driven
Step 1	Conduct background research on a Research Question	Conduct background research on a Research Question
Step 2	Choose an argument/thesis	Find, evaluate, & annotate sources
Step 3	Find sources for evidence to match your argument	Look for patterns in the sources, find gaps
Step 4	Look for counterarguments and evidence to refute them	Develop a thesis based on where researchers agree & disagree in the field
Step 5	Outline the points of your argument	Write an outline based on the patterns and gaps you found
Step 6	Write paragraphs that support your thesis with evidence/quotes	Write paragraphs that support your thesis by synthesizing sources
Step 7	Revise	Revise

Literature Reviews: Catching up with Old Friends

What do you do when you meet an old friend? You ask,

“How are you?

What have you been up to?

Fill me in!”

Literature Reviews are like getting filled in by an old friend. Only this time, you’re explaining how a field of research has gotten to the present (like how far hoverboard technology has come). But like a conversation with an old friend, you want to review only the details most relevant to the situation. You don’t usually give a moment-by-moment chronology of what you’ve done in your life (no one has time for that); rather, you talk in terms of categories–work, family, travel, etc. This is like the synthesis that happens in a Literature Review. As you read sources about a specific topic, you’ll look for themes, for similarities and differences, for points of agreement and disagreement, for gaps in the research that haven’t been filled in yet. Those themes become the categories you’ll talk about in your literature review so your audience will understand the big picture about your topic.

Literature Reviews in the Sciences

Grant Proposals

Any grant proposal submitted to request research funding begins with an extensive literature review to justify the need for the research funds. If you can prove there’s a gap in knowledge, it makes it that much easier to convince your audience to give you funding to fill that gap.

IMRAD Articles

The Introduction of an IMRAD article includes a literature review. Photo by Tom Toyosaki on Wikimedia Commons

IMRAD (pronounced “im-rad”) stands for Introduction, Methods, Results, and Discussion and is the most common genre published in the social sciences and sciences. Most of the sources you gather will likely be IMRAD-format papers. The I in IMRAD stands for Introduction and usually consists of a review of the literature on the authors’ research topic. The author(s) usually use the Introduction section to report on the published literature about their research topic and reveal the trends and gaps in current research. An added benefit to beginning an article this way is that by showing the gaps in the research, the author(s) can justify their own research and explain the significance of the topic they chose to examine. Clever!

As you might guess, the sections following the Introduction (Methods, Results, Discussion) describe the primary research the author(s) conducted to answer their research question. First they report on their quantitative and/or qualitative Methods (M in IMRAD) including statistical analyses. Then they publish their Results (R in IMRAD). Finally, the author(s) embark on a Discussion (D in IMRAD) of their results in the context of the greater field of research and make suggestions for future research. This starts the research cycle over again as someone else reads their article as part of their own review of the literature and discovers a gap in the research that can be filled by new primary research. 

Published Literature Reviews

In the world of science and social science, literature reviews can also be published on their own. For example, if someone does an extensive investigation into an important topic, the publishers of academic journals will often publish that literature review on its own to help other researchers understand that topic better.

Popular Literature Reviews

Lest you think nerdy academics are the only ones who rely on literature reviews, recall the last time you went on Wikipedia. If you think about it, Wikipedia is really just a giant literature review on millions of topics. Although the information on Wikipedia is not formally peer-reviewed like the reviews published in academic journals, they do cite all their sources and frequently revise to keep the information current. Clearly there’s a market for relevant information. If you really want your mind to explode Inception-style, look up “Wikipedia” on Wikipedia and you’ll find a literature review about a literature review.