How do you start?
Where do you begin when developing a search strategy? Start from what you know! You probably have a few articles you feel are right on target for your research question, or at least ones that are close to your area of interest. You might have literature reviews (standard or systematic) that relate to it. All of those will yield valuable terminology, authors, references, and other information that can help you design an effective search.
You'll start with lots of exploratory searches to determine the most useful vocabulary and databases on which to focus your efforts. The more thoroughly you document your efforts, the more comprehensive and successful your final searches will be. Below are some strategies that will help you with this process.
Unlike most projects, there is a very structured way of searching for Scoping Reviews. We like to think of it in 3 stages even though to some extent these stages occur simultaneously.
Exploratory searching starts the moment you first have the idea to write a review! You want to have an idea of what literature exists before putting together a protocol or developing your Research Question. There are a number of things that you will accomplish through exploratory searching.
Developing a strong search strategy is an essential part of the Scoping Review methodology. Searching systematically means that you have one search string that you use in your identified databases that will capture the greatest amount of relevant sources possible with the least amount of bias. If you're not careful, search strategies can introduce bias into the process. That is why including a librarian in the process is a best practice for Scoping Reviews.
Once you have fully tested and edited your search strategy, and you are comfortable with the number and quality of search results it is returning, you will conduct the "final search." This doesn't mean that you won't do any searching after that, it just means that this is the search that you report on in the methods section of your paper. Be sure to document the full search strategy, it's translation for different databases, the date the search was conducted, and the total number of search results gathered from each database. These are all items that you will include in your methods section.
Supplementary searching helps you pick up additional sources that your database search may have missed. There are a variety of strategies that can be used for this stage. Be sure to keep track of these searches. You'll want to reflect them in your PRISMA Flow Diagram and the methods section of your paper.
Searching is an iterative process, so don't get discouraged if it takes longer to develop your search strategy than you anticipated. During protocol development, you will have identified relevant databases, search terms, and studies. These will help you build your ultimate search strategy that you will report out in your methods section (the more detailed and transparent you are about this process, the better, so it helps to keep track).
There are two kinds of search terms: keywords and controlled vocabulary.
Best practice is to use both in your search.
When you being brainstorming keywords:
Consider whether there are different forms of a word that interest you. In library databases, searching for any ending of a word is called "truncation." Frequently you can use a * to truncate a word, but the symbol can vary among different databases. In some cases, you can use a "wildcard" to find alternative spellings that fall inside a word, rather than at the end.
Some examples for two popular databases are below. Different databases allow for different truncation and wildcard options. In the examples below, you'll notice that PubMed allows for truncation (use the * symbol) but not wildcard searching. APA PsycInfo allows for both: * for multiple characters, # for one optional character, and ? for exactly one character. Please look at the help page of the database you are searching to learn which symbols are used.
Terms may be spelled differently depending on the researchers' language background
Abbreviations may be useful
Singular, plural, and more
Some words have even more forms
Content on page has been adapted from University of Texas Arlington Libraries, Scoping Reviews Guide, and UCONN, Systematic Searching for Evidence Synthesis, CC BY-NC 4.0