Library Skills@UCL for NHS

If your search does not find the results you were hoping for, don't get disheartened. Searching is an iterative process, meaning you will need to revise and revisit your search several times to improve your results. This is an important part of the process.

One simple way to refine your search is to use limits or filters available in the database or resource you are using. These usually look like check boxes for you to select.

• Limits or filters can be used to focus your search. Common limits are criteria such as date range, language, or type of material.
• Sometimes you can see limit options when you carry out your search, especially if using an Advanced search. More often, limits are available after you have carried out your search and can be applied to your results.
• The type of limits available and how to use them varies - make sure you check the help pages for the resource you are using.
• Apply limits one at a time, so you can see the effect they are having on your results. Using too many limits might narrow your results too much.

Limits can be an effective way to focus your search but there are some cases where you should use them with caution:

• Full text: Databases often have a 'full text only' limit. Don't be tempted to select this option. Instead make sure you have accessed the database via the NHS Knowledge and Library Hub, and have signed in with your NHS Athens account. See the advice in this guide about how to obtain full text.
• Topic: using limits called 'subject area', 'category' or 'topic' can look appealing but it's not always easy to tell how subjects are defined - you might miss some relevant results.
• Humans: selecting the option to limit to humans can also be problematic. It may be fine to select this option if you are doing a quick search for a few relevant papers on a topic but, if you select this limit, you will only find papers that the database has tagged appropriately. You are quite likely to miss relevant papers and your search may not be as comprehensive as you would like.

For some tips on how to refine and edit your search, see our page on how to improve your search: