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Research Services

Literature Searching 

The time and resources required for the literature search are based on the requirements of your project. Depending on various aspects of your project including the thoroughness required, the type of information being sought, the time range of literature requested, and the need for gray literature, the search strategy and time required to complete the search will vary. In scoping your project, our team will complete an initial search of the literature in order to review the breadth of information on the topic as well as to develop keywords for search string development, however, the search phase can only take place once the project is fully scoped and the strategy/search strings have been developed and tested. 


Traditional Peer-reviewed literature 

Traditional peer-reviewed literature consists primarily of journal articles that have been submitted for publication to scholarly journals and which have gone through an evaluation process in which journal editors and other experts critically assess the quality of the article and the scientific merit of the research. Peer-reviewed articles can also go by the term "refereed articles" or "scholarly articles". A Journal may publish a number of different types of articles. It is important to understand the types and roles of these variations when considering both the research and writing of publications. In the scoping phase, our team will provide suggestions on which databases and platforms should be considered. Once the search strings have been developed and reviewed by the team, the research librarian will develop search syntax to translate the string to the selected databases, run the search, document results, export records, and import the results into the project's library.


Gray literature

Gray literature is material that is published outside of the traditional commercial publication system. While some gray literature may have gone through a rigorous internal peer-review process (government reports, theses & dissertations), much of the gray literature available has not been peer-reviewed. Due to the inherently decentralized publication method, gray literature can also be difficult to find, procure, describe, and manage. However difficult, gray literature can also be a critical component when assessing the known information on a topic. Gray literature can often be an avenue to publish studies that are less significant, and therefore, less likely to be published in academic journals, which have a strong bias in publishing studies with more significant effects. Once a project is scoped, our team will review potential gray literature resources that are relevant to the research project. Gray literature searching and the work to create metadata for each item can greatly increase the time required for a project but may be warranted.  


Database & Platform Searching

When searching for scholarly articles the primary method of discovery is through literature and citation databases and platforms. Traditional academic literature databases are developed by publishers and provide either abstract, full-text, or a combination of both on a particular subject area. Other platforms such as Web of Science may have specific indexes and cut across individual publishers and research fields. These types of platforms normally base their search on title, abstract, and other non-full-text metadata. Once a project is scoped, our team will work to identify the most relevant databases available, including open and subscription-based sources. Our research librarians will often develop and test various search strings in an effort to build the most effective search. Our practice is to maintain documentation on string development in order to help you understand how different strategies may affect the literature gathered. Once a final string is developed, this string must be translated to fit the syntax requirements of the various databases. A record of the string, filters, and results is maintained to ensure transparency and reproducibility. 


Emerging Search Methods & Tools

While some projects are more straightforward, others require the use of methodologies outside of traditional database searching. During the scoping of your project, our team will analyze the project and recommend various methods to use in the search. Non-traditional discovery methods may be used to supplement a traditional search or in order to expedite the search and screening. In recommending search strategies, our team can explain why these methods may be useful in your case. In line with our goal to ensure transparent research processes, our team works to document each process and ensure that you have confidence in the information delivered. To see the types of tools used as a part of these search methods, see our page on advanced research tools.

Select Readings on Search

Rethlefsen, M. L., Kirtley, S., Waffenschmidt, S., Ayala, A. P., Moher, D., Page, M. J., . . . Group, P.-S. (2021). Prisma-S: An Extension to the Prisma Statement for Reporting Literature Searches in Systematic Reviews. Syst Rev, 10(1), 39.

MacFarlanea, A., Russell-Roseb, T., & Shokranehc, F. (2021). Search Strategy Formulation for Systematic Reviews: Issues, Challenges and Opportunities. In arXiv. Retrieved from

Foo, Y. Z., O'Dea, R. E., Koricheva, J., Nakagawa, S., & Lagisz, M. (2021). A Practical Guide to Question Formation, Systematic Searching and Study Screening for Literature Reviews in Ecology and Evolution. Methods in Ecology and Evolution, 12(9), 1705-1720.

Bethel, A. C., Rogers, M., & Abbott, R. (2021). Use of a Search Summary Table to Improve Systematic Review Search Methods, Results, and Efficiency. Journal of the Medical Library Association, 109(1).

Schoones, J. W. (2020). Redundancy of Terms Is Not an Error but Plays a Positive Role in Composing Search Strategies. Journal of the Medical Library Association : JMLA, 108(1), 118-119.

Gusenbauer, M., & Haddaway, N. R. (2020). Which Academic Search Systems Are Suitable for Systematic Reviews or Meta-Analyses? Evaluating Retrieval Qualities of Google Scholar, Pubmed, and 26 Other Resources. Res Synth Methods, 11(2), 181-217.

Gusenbauer, M., & Haddaway, N. R. (2020). What Every Researcher Should Know About Searching - Clarified Concepts, Search Advice, and an Agenda to Improve Finding in Academia. Research synthesis methods, 12(2), 136-147.

Nakagawa, S., Samarasinghe, G., Haddaway, N. R., Westgate, M. J., O'Dea, R. E., Noble, D. W. A., & Lagisz, M. (2018). Research Weaving: Visualizing the Future of Research Synthesis. Trends in Ecology & Evolution, `(3), 224-238.

Cooper, C., Booth, A., Varley-Campbell, J., Britten, N., & Garside, R. (2018). Defining the Process to Literature Searching in Systematic Reviews: A Literature Review of Guidance and Supporting Studies. BMC Medical Research Methodology, 18(1), 85.