A literature review is an essential part of the research process. It helps you to understand who else has worked on your topic, methods that have been used to investigate this topic, and results/outcomes from similar studies. Your literature review must be extensive enough to prove that your research is necessary and important.
You do not need to conduct a Systematic Review. A Systematic Review is a research methodology where you attempt to gather all relevant literature describing a narrowly defined question. You may use a systematic technique to ensure you have searched relevant databases thoroughly, but your literature review does not need to be as extensive as a Systematic Review.
For a literature review, expect:
- That you will read two articles or book chapters for every one included on your reference list.
- You will need to search 2-6 subject-specific databases containing articles, book chapters, dissertations/theses, and other scholarly output.
- Your goal is to be thorough: expect to use both keywords and indexing terms to search databases
- You may need to use statistical sources, newspaper articles, articles from popular press magazines, reports from government organizations, or other types of unique sources in your review. These are unlikely to be a major part of your literature review, but can help to prove that a problem is widespread and deserving of research attention.
1. Define your question-- develop a hypothesis or research question. For example, "If we teach nurses to use asthma puffers correctly, does this increase patient-reported compliance with use of puffers and increase the rate of refills?"
2. Consider which databases would best provide information on your topic. Databases tend to focus on disciplines or subjects. If your research is about clinical use of drugs, you may only need to use clinically-focused databases. If your research concerns motivation for behavior, you may want to use psychology databases. If your research question is about economics of drugs, you may want to use business/economics-focused databases. Use this list of databases on this page or talk to a librarian to find the best databases for researching your question.
2. Break apart your question into concepts. With the question above, major concepts include nurses, asthma puffers, drug compliance, technique, refills.
3. For each concept, brainstorm synonyms. For example, puffer= inhaler, Flovent (or other brand names), etc.
3a. If using an indexed database like PubMed, look for the preferred indexing term for each concept and add it to your synonym list.
4. Combine the synonyms in your database. Use OR to connect synonyms. Use AND to connect different concepts. For example: (Nurse OR nurses) AND (inhaler OR puffer) AND (education OR training OR instruction).
4a. It is sometimes easier to look for research covering parts of your question rather than the whole. It is unlikely that there has been research on exactly your topic (nurses, and asthma puffers, and instruction, and compliance, and refills). Consider looking for research on nurses and inhalers; instruction with inhalers and if that affects patient compliance; use of puffers and refill rates; or other ways to break down the question into smaller parts.
5. Examine the results in your first database by reading the abstracts. Add to your list of synonyms by seeing what terms are used in the abstracts, and consider re-running the search with additional terms. Create a list of materials from this database that seem relevant. Next, download the full text of articles, book chapters, etc. on your list. Get older articles in print from the library's print collections. Repeat this process in your other databases.
6. Read the materials you found in step 5. Consider whether the information you have found allows you to demonstrate:
7. If you cannot demonstrate each of these, repeat steps 4 and 5 until you can.
8. Write your literature review, summarizing why your question/problem is important, other methods that have been used to investigate this problem and what they have found, and explain why your research question will help fill gaps in current knowledge. You can consider using the FINER criteria (Feasible, Interesting, Novel, Ethical, Relevant) to ensure you have covered the key aspects of the topic in enough depth. You will likely cite/reference about half the items you read. Your goal here is to select enough materials to demonstrate that you know this topic, without overwhelming your audience.
USC subscribes to over 700 databases, so only the primary databases you may use are listed here. If these do not cover your topic fully, examine the A-Z list of databases and read descriptions, or ask a librarian for help.
Basic sciences databases
Social Sciences databases
These databases include multiple subjects. They are useful databases for looking for landmark studies; determining if your topic is well-studied by another subject (as this would lead you to select a database that focuses on just that subject); and ensuring you did not miss research published in prominent scientific journals.
Use these handouts to get information on citing and writing; contact the Norris Medical Library with questions.