Academic Writing Guide

What is a literature review?

A literature review is a collection of articles, books, reports, and other sources which summarize an area of research or theory. One of the first steps in doing a research process is to do a literature review to get a sense of what research has been done in your area. Sometimes a literature review is wrapped up in the introduction, other papers have a separate section, and in some case like a systematic review it is a whole paper itself. 

Basically any literature review does three things:

• Summarize current and past research published on a particular topic.
• Organize this research to show relationships between different studies and articles as well as adding to the readers' overall understanding of the topic. 
• Gives the reader a picture on where the gaps are in the research, and/or how your study closes those gaps.

Process to create your literature review 

There are four steps to creating a literature review:

1. Defining your topic
2. Searching the databases for available research
3. Group the research you found by topic
4. Identify themes within the research 

Most people are used to doing the first two steps in the preparation stage of research. What makes the literature review process slightly different is that you are not just looking for literature to support your point, you want to also include literature that does not prove your point. The purpose of the literature review is to give the reader is a full picture of the available research on a certain topic. Sometimes a reader will identify a topic in a literature review that stimulates interest, and they will do their own research. In this way, a literature review can become a secondary source itself, because it summarizes past research. 

Types of Sources in a Literature Review

Is one type of resource more important to use than the other? 

It is really important to use a combination of all three types of sources when creating your literature review. Students often ask if one type is more important than the other to include. Remember the point of a literature review is to present the reader with available research on this topic. The goal is include original research which the reader can retrieve and interpret for themselves. For that reason the majority of resources you should cite in the text of your literature search should be primary. In other words original research or data interpreted by only those directly involved in the study. Articles that were created by individuals not involved with the original study are secondary and tertiary. The advantages of the latter two types of resources is that can lead you to excellent primary sources. The reason these sources are so important is that databases can only retrieve so much. Using sources to find other sources may reveal sources not easily accessible in databases. 

Finding Sources for a Literature Review in the Boxer Library 

Now that you know what primary, secondary, and tertiary sources are, you need places to find them. The library has many different databases you can use to locate materials on your topic. Remember that if the library does not have the full text immediately, you can place an Interlibrary Loan request to obtain a copy of that article from another library. 

Boxer Library Resources to Find Literature

Library Resource	What is it?	When to use it?
CINAHL Complete	Provides full text access to hundreds of nursing and allied health journals indexed in the CINAHL (Cumulative Index to Nursing and Allied Health Literature). Additional materials include Evidence-Based Care Sheets and Quick Lessons which provide concise overviews of diseases and conditions and outline the most effective treatment options.	If you are looking for information normally found in allied health or health policy. Some of these topics are not listed in PubMed.
Cochrane Library	A collection of databases containing high quality, in-depth evidence to assist in healthcare decision making. Includes the Cochrane Database of Systematic Reviews, which provides peer-reviewed systematic reviews and protocols.	If you are looking for systematic reviews in the health sciences. Remember systematic reviews are a great place to find references. (secondary source)
LibrarySearch	The Boxer Library's new next-generation discovery service. One search box is all you need to search multiple databases at one time. Search for articles and other information by keyword or by title.	Use if you are searching a general topic.
Ovid Medline	Provides advanced features for searching the National Library of Medicine's MEDLINE database, which contains over 22 million biomedical citations.	Use if you are looking for articles related to biomedical fields.  Use if you are using Medical Subject Headings (MeSH) Use if you want to easily limit by article type
PsycInfo	A database of peer-reviewed literature in behavioral science & mental health.	Use if you are doing research related to psychology or behavioral sciences.
PubMed	A database that includes over 22 million biomedical citations from MEDLINE. While it does not provide full text access for every citation in the database, PubMed will link you to all full text articles that are currently available through the Boxer Library electronic collection.	Use if you want the newest research in the biomedical sciences. Use if you want to use limiters such as publication date, article type and more.

How to Evaluate Your Sources

One very important part of any literature review process is to evaluate your sources. You want to include the sources that are most relevant to your topic as well as those of the highest quality. There are a few questions you should ask yourself when reviewing any resource before including it in your literature review.

Who wrote it?

• Determine who the author is, and why this person is qualified to write on this topic. 
  • Is this person a professor, expert in this field, or researcher?

When was the material created?

• Is adding older material acceptable? 
  • If the purpose of the literature review to gather a history of a topic, you may want to include articles published in any date.
  • If the purpose is to review the newest research, you may want to restrict your results to five or ten years. 

How was the study designed?

• One of the ways to evaluate a study is to see how it was structured or set up. 
  • Answer the following questions:
  • How many participants were in the study?
    • If it a study has a small sample size, it may not be the strongest evidence to support an idea. However be aware that some topics only have a few studies. In that case a smaller size is acceptable, because larger ones do not exist. 
  • What percentage of the participants who began the study, finished the study? 
    • To get the most accurate picture of the data most of the participants should finish the study. If not, the data may not represent the full picture of what is going on, and researchers must make assumptions or conclusions without the full set of data. A large dropout rate may indicate problems with the methods. 

Are there any signs of bias?

• One important thing to look for in any study is evidence of bias. 
  • Answer the following questions:
    • Is evidence from different perspectives included?
    • Is it a blind study? 
      • In other words are the participants and testers aware of what groups subject are placed in? A double-blind study refers to the fact that neither group knows where they are assigned. This can cut down bias because there are no preconceived notions affecting the outcome of the data.