Systematic searching: 9. Evaluating the search result

Once you have completed your search, it is worthwhile to look at the results and reflect further:

• Do the search results match what you searched for?
• Are there any relevant terms missing from the search?
• Are all the terms you have used relevant and useful for the search?
• Are there more terms in the search results that you could add to your own search?
• Do any terms consistently produce the wrong search results?

You can evaluate your search with the PRESS checklist, a condensed version has been produced by the Karolinska Institutet. If you wish, you can consult the original checklist (see Table 1 in the linked publication). 

In our example topic, hand hygiene skills of nursing students, one could consider whether it is necessary to include terms related to skills in the search, or whether it is sufficient to search using only the terms "nursing students" and "hand hygiene". If you search using search terms already related to nursing education or student nurses, do all search results already automatically relate to competencies, skills or competencies acquired during studies, without including terms related to competencies?

You can compare your search strategy with other search strategies on the same topic.

• Search strategies can be found in systematic reviews and their protocols, for example in the Cochrane Library or the JBI EBP database.
• Systematic reviews can also be searched for in MEDLINE and CINAHL, for example, using "systematic review" as a search term.
• You can also try searching for systematic reviews in Andor by adding "systematic review" as a search term.
• The protocol of the review is often linked to the review itself.

The appropriate number of search results is not straightforward, especially when doing a systematic review:

• If the subject has been studied extensively, the set of search results will naturally be large.
• If, on the other hand, there has been very little research on the subject, the search may have to be broadened to include all articles on the subject. 

It is essential that you can justify your search results when reporting your search, so a well-designed and thought-out search plan will also help you in evaluating the result. Good luck with your search!