4.6: Expand and Narrow Search Results

Refine your results:

At this stage, you should narrow the number of results to a low enough number that you can reasonably review all the citations and librarians can help you refine your searches for your topic!

You should narrow the number of results to a low enough number that you can reasonably review all the citations. You do not have to read the full text of all of them, just the citations and abstracts to evaluate which seem worth reading. A good range would be anywhere from 50-150 to get a scope of the literature. If you’re seeing fewer (as our example above had only 30 results), that’s still a great start. You’ll want to review those citations. Then consider how you might expand to learn more about how the field has covered these topics.

Expand results:

If you have very few or even zero results, how can you expand?

If you combined all of your Venn diagram's circles together, you'll likely retrieve zero results. Remember, the combination of all the circles is your topic, and part of the reason to do a literature review is to show why it's relevant to study your topic. If you find many "perfect" articles on your exact topic, that means your topic is already heavily researched. Therefore, finding few sources can potentially indicate this topic has not been well studied.

Here are a few different ways you might be able to expand results:

• Search for only two of your Venn diagram circles, rather than 3 or more.
• Include more synonyms and related terms to one or both of your search sets.
• Try a different database. Perhaps the one you started in isn't the best for your topic.
• Look outside your discipline for articles in other fields. Keep in mind that if very little has been written on your topic, you might want or even need to include studies from other disciplines.
  • Example: I published a case study about upper level graduate students ("peer teachers") teaching information literacy sessions for me. Very few librarians had published about doing this, but many in the medical field had, so I used their case studies in my literature review. The medical discipline's articles helped me show the benefits of having peer teachers.
• Expand your criteria beyond your exact interest.
  • Example: In the same case study above about peer teachers, I also included articles within my discipline about student workers and "peer tutors". Neither were what my study was about, but these strengthened my case that:
    • My field wanted student workers to take more responsibility, but
    • My field was not yet publishing about my particular topic.

Narrow results:

Sometimes combining two search sets will retrieve too many results.

• If you have thousands or more results:
  • Add a third term from your Venn diagram; or
  • Consider if there's a narrower way to phrase one of the searches. If you're searching for BIPOC, could you narrow to Black Americans? Or if you're searching for Therapy, could you choose a particular treatment?
• If you have a few hundred results, try adding limits.

Limits or Filters:

You’re likely already familiar with adding some limits while you’re searching. Depending on the database, you’ll have different limits available to you, but here are a few common ones.

Filters found in many library databases

Filter	Helpful Tips
Peer-reviewed	Most research databases have a filter called ‘peer reviewed’ or similar that accurately identifies peer-reviewed works. Peer-reviewed means that someone other than the author reviewed and provided feedback on that work before publication. Being peer-reviewed elevates the work as it has been deemed valuable to share with the field by experts. You usually want most of your citations to be peer-reviewed. However, scholarly books, edited book chapters, dissertations, and theses are not peer-reviewed. You might want or need to cite a book or chapter, especially for background information. If you’re working on a dissertation, you’ll want to review others’ dissertations to: 1) ensure you aren’t replicating someone else’s work inadvertently; 2) explore their citations since dissertations have long literature reviews which might be useful for you to read; and 3) get a sense of how others have formatted their literature reviews (keeping in mind that just because they did it, does not mean it was done well or in a way your committee prefers).
Year published	Check with your faculty on the year range you should start with for your field and your topic. For many fields, it’s best to start by limiting to the last 5-7 years, but this depends on discipline and topic. Later, we’ll discuss exceptions to recent works, but for now it’s usually best to start recent.
Location	Here is a chance to consider positionality. Does the location of the study matter? It depends. If your topic involves a particular region (perhaps a sociological study of a certain group of people), then location is critical. Unfortunately, this location limit in most databases comes from the lead author’s institution. This can be problematic. For example, imagine a study about immigration in Central America. Perhaps the first author is Venezuelan, but currently works at a university in Germany. The location for that study would be Germany. This makes it difficult to effectively use the location limits to find studies about particular regions.
Full Text	While you might automatically want to use this limit, I caution you against it, especially for dissertation. Even if your library does not have full text of a particular source, they can likely get it for you through interlibrary loan. Check with your librarians on how to do this. You definitely do not want to miss important sources simply because there was no immediate access to full text.
Methodology	While there are times you’ll want to narrow by a type of methodology, be careful. At this stage in your searching, you’re looking for the context of what research has been done on your topic. Even if you already know that you want to do a qualitative study, you still need to cite all sources, even those which are quantitative.

Activity: Refine your searches \(\PageIndex{1}\)

Play around a bit with these suggestions. For now, just note how many sources you're finding with different combinations of terms and applying various filters.

Next Steps

In the next section, we'll cover how to evaluate the results you're finding, without wasting your time reading all of them.