Text mining is a way to help you identify search terms by using analytic software to check text (such as key articles, groups of abstracts etc.) for recurrent words or phrases. Some free text mining tools are listed below.

Health-related: PubMed is a free version of Medline, so its abstracts and citations are easily mined. Here are some really useful tools if you are reviewing in this field:

• PubMed PubReMiner - type in keywords or your research question and the tool will display a table of the most common journal titles, authors, keywords and MeSH (Medical Subject Heading) terms related to the topic.
• Yale MeSH Analyzer - If you have a few key articles from your gold set and type in a list of PMIDs (PubMed IDs), the major MeSH terms will be displayed.
• PubVenn -  presents Venn diagrams showing the relative size of concepts and where they overlap. This is useful for a quick visualisation of where to focus your search.
• MeSH on Demand - from the National Library of Medicine, this tool enables you to paste in text, such as your research proposal or abstract and retrieve suggested MeSH headings. It also provides links to similar articles.

All Disciplines:

• TerMine is a tool that allows for blocks of text to be mined for keywords. Paste in a whole article or chapter and the most common words and phrases will be extracted
• Voyant Tools -  Includes both text and visual outputs. Paste in a block of text, a URL, or even an RIS file. Keywords and phrases are analysed and also examined for relationships.
• VosViewer - again, paste in text and see diagrams of key terms and their relationships to each other.

Search filters (sometimes called hedges) are pre-tested search strategies designed to find certain types of articles in a particular database. They aim for search sensitivity and precision and can be very useful if you find one you can use or adapt for your topic. Most published filters are in the health fields - please let us know if you find others in different disciplines!

Here are some examples:

• Lowitja Institute - Filters for Aboriginal & Torres Strait Islander health and welfare literature.
• CareSearch - PubMed searches ready-constructed for all aspects of palliative care, as well as bereavement, dementia, heart failure, lung cancer, residential aged care and costs of care.
• Cochrane Handbook - Part 2, Section 4.4.7 - Search Filters
• ISSG Search Filters Resource - Information specialists in the UK have developed these filters to identify specific study designs, such as guidelines, mixed method studies, outcome studies, quality of life and many more.
• McMaster University - Hedges - Filters for diagnosis, therapy, prognosis, etiology/harm and economic analysis for Medline, Embase and PsycInfo.
• PubMed Clinical Queries Filters
• Health Libraries Australia - Live PubMed searches related to each of the nine NSQHS Standards (Advance Care Planning, Blood Management, Delirium, etc)