Systematic Reviews & Evidence Synthesis

What is "Exploratory Searching" in Evidence Synthesis?

Exploratory searching is the process of conducting well-designed but non-comprehensive searches to help develop and refine your project idea.

Exploratory searching occurs on and off throughout the entire pre-planning and protocol writing phases.

Why do Exploratory Searching in Evidence Synthesis?

The primary purpose is to help you develop and refine your research questions and inclusion/exclusion criteria.

Develop a well-designed but non-comprehensive search strategy to help develop and refine your project idea.

Locate Existing Review Articles

To locate existing review articles, run your reasonably thorough search strategy in both your selected primary database and general database.

Then try the following methods, one at a time:

• If the database has it, apply the "systematic review" or "reviews" filter
• Add AND (review) to your search
• Add AND ("systematic review" OR "meta-analysis" OR "scoping review") to your search

What if you locate an existing review on your topic?

• How old is the review? Does it warrant an update?
• Was the review conducted well or are there major flaws that you could improve upon?
• Is there an adjustment to your research question that is valuable and would not duplicate their results?
• Can you learn something from the search design or other processes in this review that can help you conduct your own review?

Locate Proposed Review Articles

Search for publicly registered review protocols. If you find one on your research question, then another team is already working on a review on your topic.

Places to search include:

• Journal/Repositories that Specialize in Evidence Synthesis: There are journals and repositories that specialize in publishing or collecting evidence synthesis projects. Some of these are field specific and some are not. Ask disciplinary experts and librarians for recommendations.
  • Some of the best known include:
    • Campbell Systematic Reviews (social sciences)
    • Cochrane Reviews (healthcare and medicine)
    • Collaboration for Environmental Evidence (CEE)
    • Systematic Reviews for Animals and Food (SYREAF)
    • What Works Clearinghouse (education)

Assessing Scope

Refining the scope of an evidence synthesis project is one of the hardest parts of planning!

These projects rely on existing evidence. You can only successfully complete a project for which a) there is enough evidence and b) the project has not already been done.

The exploratory searching phase of project planning should help you identify a research question and project aim that meets both of those criteria.

Assess the volume of literature

• Develop a keyword search that is complete enough that you feel like you can make a good estimate on how many results you would ultimately get for screening.
  • Keep in mind, you cannot just decide to make the search narrower to reduce results numbers!
    • If the results are too large you can narrow (focus) the research question, OR
    • Discuss with a librarian how to properly apply search techniques that increase precision without reducing the necessary sensitivity (comprehensiveness) of the search.

Assess the types of evidence

• Not all types of evidence are appropriate for answering all types of questions. Make sure you are finding the right type of evidence for your research question.
• Do your initial ideas for screening (inclusion/exclusion) criteria match with the types of evidence you find? Do you find a few articles that would be included but not too many?
  • You might need to alter your criteria and/or your research question or aim in order to better match the types of literature available.

Assess where evidence is produced and published

• Keep an eye on the types of articles you are finding. Do any of them cross over into other fields of expertise (psychology, economics/business, sustainability/environmental studies, nursing, etc.)?
  • This may suggest you will need to add databases and terminology common to another field in order to comprehensively locate all relevant evidence.
• Who is represented and who is not represented in the evidence you have found?
  • Consider if your project would benefit from adding databases that better represent scholarship from the Global South, Africa, Indigenous communities, or other groups often underrepresented in Western collections of the literature.

Find some target/seed articles

Seed articles are some of the best proof of viability you can find!

• Make certain the articles really do match with your research question and screening criteria.
  • If you alter your research question, project aim, and/or screening criteria, make certain all your seed articles still match.

More details on seed articles below.

Seed articles (also called "target" or "seminal" articles) are 2-8 articles on your topic that you think will make it though your screening process.

• If you cannot find at least a couple articles that you think will make it though your screening process (applying inclusion/exclusion criteria), then you are at risk of producing an evidence synthesis project than cannot make any practice or policy recommendations.
  • It can be valuable to conduct and publish an evidence synthesis project demonstrating a lack of evidence, but you should check with program advisors or potential publishers to see if they accept or publish those types of projects.

• Use these articles to refine your inclusion/exclusion criteria, research question, and your term list of keywords and controlled vocabulary.
  • Ask yourself: Is this article going to make it through my inclusion/exclusion criteria? Does it meet my research goal/aim? If not, what needs to change (re-scope the question, alter the screening criteria, refine my concept definitions, discard the article)?
  • Ask yourself: Do I use all the relevant keywords from this article in my search strategy? What controlled vocabulary is applied to this article and should those be in my search strategy?

• Your final comprehensive search strategy should locate these seed articles!
  • If it doesn't, contact a librarian for further assistance.
• Seed articles can be used to communicate with librarians and other experts about what types of evidence meet your goals.