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Expert Keyword Searching

Building a Search Strategy

You can save yourself some time and frustration if you plan your search strategy before you start looking for articles. It's like having a shopping list before going to the grocery store. Of course you may be fuzzy on some of these items to begin with, and that's OK. You can refine your search strategy as you go.

You may also want to keep a record of your search strategy (and the decision making that went into it), because having a record of what, where, and how you searched can help you replicate your search later or make modifications to improve your results.

What's in a search strategy?

  • A focused question, possibly in the PICO(T) format.
  • Search terms (consider both keywords and subject headings)
  • An idea about the types of evidence you are looking for (e.g. statistics, original research, personal experiences, etc.)
  • Where you'll search for that evidence - databases, search engines, individual websites, etc.
  • Filters/Limits you'll apply to your search
  • Inclusion/Exclusion Criteria - how you'll decide which articles, etc. you'll cite

For more about all of these elements, look at the boxes below and in the blue tabs on the left. 

PICO Questions and Search Strategies

Think of a search strategy as a shopping list for evidence. When you're looking for evidence, there is probably specific types of evidence fitting specific criteria that you need. Planning your strategy in advance can save you some time and keep you organized. Furthermore, having a record of what, where and how you searched can help you replicate your search later or make modifications to improve your results.

Before you start a topic search for a literature review or other assignment, ask yourself these questions:

  1. What question am I trying to answer?
  2. What types of evidence will I need to answer my question?
  3. What search terms will I use to find evidence?
  4. Where will I search to find the evidence?
  5. What criteria will I use to choose the best evidence?

1. What question am I trying to answer?

Placing your research question in the PICO(T) format can help you ensure that your question is answerable. If your question doesn't fit PICO(T), it might be too specific (not enough results) or too general (too many results) to research using the databases. The video tutorial below will take you through the process of developing a PICO(T) question.

This PICO(T) Templates worksheet can also help.

2. What types of evidence will I need to answer my question?

A PICO(T) question also makes searching easier because the type of question determines what type of evidence you should look for:

Type of PICO(T) Question Type of Evidence Needed to Answer
Diagnosis Studies reporting performance characteristics
Therapy Clinical trials
Randomized Controlled Trials
Systematic Reviews (of Clinical Trials and RCTs)
Etiology Cohort Studies
Case Control Studies
Systematic reviews (of Cohort and Case Control Studies)
Prognosis Cohort Studies
Meaning Qualitative Studies: Ethnography, Phenomenology, Grounded theory, Focus groups


Remember that some types of evidence are stronger than others. Often evidence is shown in a pyramid, in which each ascending level represents a different type of study design and corresponds to increasing rigor, quality, and reliability of the evidence.  In other words, as we ascend through these different study designs, we become more confident that their results are accurate, have less chance of statistical error, and minimize bias from confounding variables that could have influenced the results. (

Evidence Based Practice Pyramid

Always aim for the highest level of evidence appropriate to your question type. For your DNS 820 lit review, you will probably be asked to use original research studies only and not systematic reviews. However, if you find a systematic review that answers your question, you can use it to lead you to original research studies relevant to your question.