Conducting a Literature Review

Supplemental search methods include strategies that explore credible content, such as:

1. Grey literature: includes a wide range of content, including white papers and other reports not published in commercial journals or books but available from credible web sources, including theses and dissertations. Many grey literature resources are included in several guides in the library on a range of topics.  Grey literature is unpublished, so it does not suffer from publication bias and is often more current than published sources.

2. Citation relationships: scanning the reference lists of articles and theses, the included studies in knowledge syntheses, using database limiters that support: similar articles searching, co-cited articles searching, or forward citation searching  

Pay attention to:

• authors who publish on the topic more than once
• take note of those author’s keywords
• look in the article bibliography for other articles to consider
• look for the original research on a topic by following the citations through the bibliography and journal titles

3. Hand searching: a physical copy of a published journal can reveal content that was excluded from the indexing of an online journal. This method is handy for elusive topics with little obvious literature available in the online indexes, and other forms of supplemental searching have revealed little.

4. Clinical Trials registries often report on content not reflected in the published literature. The US Government and the World Health Organization provide clinical trials with searchable registries.

• International Clinical Trials Registry Platform (WHO)
• ClinicalTrials.gov

5. Direct author contact is useful for

• more information about clinical trials,  
• following up on current research not yet published
• gaining access to an article not found in the university library
• accessing important works that are older and not readily available without paying.  

Contact information is found in a variety of ways:  in online articles, in databases as part of the article data, searching out research instrument information in CINAHL, accessing institutional contact lists or websites or through professional sites such as LinkedIn.

6. Metadata is ‘data-about-data’.  There are many different kinds of metadata. Metadata is not full-text content, but contains information (data) clues to finding the item.   With research metadata, researchers and readers can use that information to find a known item, locate similar content and other information of interest or use.  

Some  types of metadata useful when conducting research:

• Reference/citation  -  metadata organized in a standardized pattern
• Reference lists - contain all the references consulted in an article or book or dissertation. 
• Online indexes - (e.g. PubMed, Google Scholar) have metadata highlighting what content exists on a topic, useful for completing a partial citation. 
• Database records contain comprehensive metadata to lead the researcher to other content on the topic, provide clues for alternate keywords to search on and help determine ownership of instruments. 
  • Articles are often tagged with the topic or with standard subject headings that lead to further linked content
  • Locating the affiliation of the author (institution) and their credentials to request permission to use an instrument.
  • Determining journal type: eg. systematic review and journal subset eg. peer review.