Preliminary search
Preliminary searching is an initial step undertaken when preparing to conduct a literature review.
Preliminary searching can help you to:
- establish a basis for a more comprehensive search later in the review process.
- determine whether there is a gap in the literature and whether your review is necessary.
- adapt or refine your research question based on the results.
- become familiar with the vocabulary and subject headings researchers use to describe topics related to your question.
Additionally, preliminary searching can aid in locating literature that is key for ensuring your systematic search is comprehensive and reproducible, known as seeding articles.
Search Planner
Use the downloadable search planner below to help build and document your preliminary search.
Seeding Articles
Seeding articles are highly relevant or influential research publications within your topic area. These articles help you to identify the diverse vocabulary and subject headings researchers use to describe your topic. They also provide a foundation for ensuring your search strategy captures key studies and may be used to test the effectiveness of a search strategy.
Finding seeding articles
There are various methods to find seeding articles on your topic. Click on the plus icons (+) below to learn about methods for finding seeding articles.
Identifying seeding articles
Inclusion and exclusion criteria are essential tools for defining which studies are relevant to your review, and can also guide the selection of seeding articles.
When identifying seeding articles, consider how well each article aligns with your inclusion criteria. This alignment helps maintain consistency and relevance in the review process.
For example, if your inclusion criteria specify experimental studies published within the last five years, focus on finding seeding articles that match these parameters. Similarly, exclude articles that fall outside your scope, such as observational studies or those published beyond your date range.
Tip
When you’ve identified seeding articles it can be useful to organise your findings. This allows you to have a clear view of the key details from your seeding articles, spot patterns between articles, or identify concepts and keywords. Use your preferred way to organise seeding articles or download our Summary Literature table template.
Identifying concepts
Concepts are the key ideas or themes that make up your research question. They represent what will be explored in the literature to address your research topic.
To identify search concepts, begin by breaking down your research question into its main components. By focusing on the essential elements of your question, you can develop a targeted and comprehensive search strategy that captures all relevant literature.
Tip
Each concept typically corresponds to an element of your research question, such as population, intervention, or outcome. Question framework tools, such as PICO, can help structure the elements of your question. Keep in mind that concepts do not always match perfectly with question frameworks. Some research questions may involve overlapping or additional themes that require consideration.
Check out Module 2: Frame your research for further information on research question frameworks.
Identifying search terms from concepts
To create a comprehensive search strategy for your literature review, it’s necessary to find all terminology used in literature to describe your concepts, these are known as search terms. Different studies may use different terminology to describe the same concept. If this variability isn't addressed in your search strategy, it could lead to relevant literature being missed in your review.
To ensure a comprehensive search strategy, analyse seeding articles to:
- Highlight search terms in articles that relate to the main concepts of your research question.
- Identify similar words used across articles to describe the same concept.
- Examine search strategies from existing reviews for inspiration and commonly used terms.
Additional search terms can be located using database tools such as thesauri, indexes and subject headings to identify controlled vocabulary terms, for example MeSH terms in Medline or CINAHL Headings in CINAHL.
Checklist for concept search terms
For each concept, make sure you check for:
Search Techniques
Search techniques are functions in databases and search engines to help perform search strategies effectively. Search techniques can help you capture search terms more precisely, broaden or narrow your search, and refine your search results.
Keep in mind that search techniques vary between databases. It’s important to become familiar with the specific features of the databases you’re using.
Explore search techniques below in more detail as they're applied to the research topic, use of social media among teenagers.
Identifying databases
Databases are a key resource for finding literature relevant to your review. Databases often cover multiple topics and no single database contains all relevant literature on a topic. In your review you need to run your search in at least two or three databases.
It's important to select databases that cover the majority of relevant literature for your topic. Carefully selecting appropriate databases ensures comprehensive coverage of your research topic and minimises potential bias.
There are platforms that allow you to simultaneously search across multiple databases. However, it's recommended to search one database at a time to ensure transparency and to utilise the unique features of a database.
How to identify databases
The following provides information on how to identify databases to search in for your review:
- Understanding discipline-specific databases
Check out our resource guides for help locating key discipline-specific databases related to your research topic. Different disciplines have databases that are essential to search for a review, such as Medline Complete for health and ERIC for education. There are also citation databases, such as Scopus for citation searching. Additionally, you may want to include grey literature in your search strategy.
- Testing database relevance
To test if you have located a suitable database to include for your review, conduct searches using simple keywords in the database. Evaluate the results to ensure they are relevant to your topic before proceeding with more comprehensive searches.
- Using seeding articles
To identify the database to build a main search, it can be helpful to find the database where the majority of your seeding articles are indexed. You can locate the databases that hold your seeding articles through the journals they were published in.
Using Ulrich's Periodicals Directory you can search for journal titles to identify the databases that hold issues of your seeding article journals.
Searching scenario
Tip
Download the Example Search Planner for further information on how each step in the preliminary search was applied to a research question.