You may have heard people refer to performing a comprehensive search, but what does this really mean? And how can you be sure your search is comprehensive?
A comprehensive search attempts to find all the relevant literature on a topic. However, without reviewing all the literature that exists in the world, there is not any way to know with 100% certainty that you have found all relevant items. The best that you can do is take multiple steps to help ensure that your search is as comprehensive as possible and strive for comprehensiveness.
The following are some standard steps to take to help you strive for comprehensiveness:
- Search Multiple Databases: There is no one database that holds all the literature published in the world. Each database contains its own unique set of content, so by checking multiple databases, essentially all the nooks and crannies where relevant articles may live, you can help increase the comprehensiveness of your search.
- Develop Search Terms: There is a lot of variability in language, and what you call something may be different from what another researcher calls something. By searching with multiple terms to describe each of your concepts, you can help ensure that you don't miss something that is called by another name.
- Keep it Broad: If your search is super focused with lots of concepts represented, you run the risk of the search being too narrow and missing valuable results. By keeping your search as broad as possible and performing more screening to sift out irrelevant items, you can feel more confident that you are not missing anything.
- Minimal Limiters: Resist the urge to apply a lot of limits to your search. The goal is to capture everything, so it is better to manually decide something is irrelevant than you not see it at all. Database limiters are also typically based on how an item was indexed for the database, so some relevant items can be missed if they did not get tagged in the way you expect.
- Citation Searching: A good practice when performing any type of search is to check the references of any included or relevant articles. You may discover a new article that was not otherwise captured by your database searches or discover a new avenue of inquiry to pursue.
- Hand Searching*: Some researchers may choose to manually scan every volume and issue of a particularly relevant journal to check for anything that may have been missed in the database searches. If you find a few articles using this method, that can be a helpful addition. However, if you find a lot of articles in this way, it can be an indication that there is something wrong with your database search.
- Grey Literature*: Not every research study results in a published journal article. If you only search for published journal articles, you risk introducing "publication bias" into your project. To help combat this and ensure your search is comprehensive, you can try searching in less traditional sources, such as government or professional organization websites, clinical trial registries, or conference proceedings to find the results of studies that were never (or not yet) formally published.
*The last two steps may be unnecessary for your HTHRHSC 4590 Course Project, but they are good to know about for the future.
