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Search frameworks

Search frameworks

Search frameworks are an aid to converting your research question into search terms that will provide useful results from a database.

There is nothing magic about a search framework (and PICO in particular), it is merely an aid to defining your search terms. 

If you need to modify your search beyond the framework, do so. If you find a particular search framework does not match your research question, you do not have to use it.



PICO is the most common framework for yes/no or A/B quantitative clinical questions

  • Patient or Population (or Problem)
  • Intervention (or Indicator for diagnostic studies)
  • Comparison (or Control)
  • Outcome

Not all topics will use all four categories for search terms when interacting with databases.

For instance, if you are comparing against  all other therapies (or against none) you might not have a search term for the Comparison or Control field. Alternatively, if you are not looking for a specific detailed outcome, you might not have an outcome search term.

There are also some variations of PICO using an extra category fo research terms e.g.


  • Patient or Population (or Problem)
  • Intervention (or Indicator for diagnostic studies)
  • Comparison (or Control)
  • Outcome
  • Timeframe


  • Patient or Population (or Problem)
  • Intervention (or Indicator for diagnostic studies)
  • Comparison (or Control)
  • Outcome
  • Study type


  • Patient or Population (or Problem)
  • Intervention (or Indicator for diagnostic studies)
  • Comparison (or Control)
  • Outcome
  • Context


or sometimes:

PICo - occasionally used for searching for qualitative studies

  • Population (or Problem)
  • Interest
  • Context


  • Population
  • Condition
  • Context



SPICE can be used suggest search terms to evaluate a service or project, mostly looking at qualitative data, and allowing some subjective judgment of benefit in relation to specific stakeholders.

  • Setting – "where?" (Booth, 2006) or "context of the service" (Booth, 2004)
  • Perspective – "for whom?" (Booth, 2006) or "user, manager, carer, information professional, [etc]" (Booth, 2004)
  • Intervention – "what?" (Booth, 2006)
  • Comparison – "compared with?" (Booth, 2006)
  • Evaluation – "result?" (Booth, 2006)

Booth, A. (2006). Clear and present questions: formulating questions for evidence based practice. Library hi tech, 24(3), 355-368.

Booth, A. (2004). Formulating answerable questions. In A. Booth & A. Brice (Eds.), Evidence based practice for information professionals: A handbook (pp. 61-70). Facet Publishing.



SPIDER was designed for selecting more appropriate search terms for searching qualitative and mixed-methods studies for topics that did not fit well within the PICO framework categories.

  • Sample
  • Phenomenon of Interest
  • Design
  • Evaluation
  • Research type

Cooke, A., Smith, D., & Booth, A. (2012). Beyond PICO: The SPIDER tool for qualitative evidence synthesis. Qualitative Health Research, 22(10), 1435–1443.



ECLIPSE is used to help define search terms for health and social care management-related information.

  • Expectation - what is the information for? [Sets the context for the search. Might not contribute to search terms.] 
  • Client group
  • Location
  • Impact - what is the expected change?  What defines success? How is it measured?
  • Professionals
  • SErvice - what(which) is the service involved? "For example, outpatient services, nurse‐led clinics, intermediate care."

Wildridge, V., & Bell, L. (2002). How CLIP became ECLIPSE: A mnemonic to assist in searching for health policy/management information. Health Information & Libraries Journal, 19(2), 113-115.


BOx the Nouns And Provide Alternative Research Terms for Each

OK, this is tongue-in-cheek, but it's a valid subset of the BUG1 technique for undergraduate subject analysis, if none of the frameworks define your topic clearly.

Write out your research topic as if you were defining it very clearly to a new junior research assistant or a colleague in a different disciplinary area. Could they explain to somebody else what your research is about?

  • Draw boxes around the nouns. Delete any that describe the level (e.g. risk, danger, level, amount, degree) rather than the plain topic.
  • Delete any word that isn't in a box.
  • For each word, brainstorm for other terms that might also be used by writers and researchers to describe the same concept. Join the terms with OR.
  • Add a set of parentheses (round brackets) around each group, and join all the groups with AND.
  • Use this as your search strategy.


Does wearing slippers increase the risk of falls in the elderly
(slippers OR "slip-ons" OR footwear) AND (falls OR tripping OR accident*) AND (elderly OR aged OR senior)


Note: this particular example could be represented in PICO as:
P - elderly
I - slippers
O - falls

1 BUG (box, underline, glance back) technique developed by Dr Geraldine Price, Southampton University
Cowen, M., Maier, Pat, & Price, Geraldine. (2009). Study skills for nursing and healthcare students. Harlow, UK: Pearson Education.