The standardised subject indexing provided by subscription databases makes it easier to retrieve relevant records. The index term Doping in Sports appearing in the example below classifies the article as being primarily about doping in sport. So if you are retrieving too many results, you may wish to try narrowing your search by specifying that some (not necessarily all) of your search terms must appear in the subject index field, not just in the title or abstract.

NOTE limiting to papers primarily about X will exclude broad reviews that, for example, cover a particular methodology applied to X, Y and Z.

NOTE that the Keywords Plus that appear in Web of Science are simply terms additional to those appearing in the title and abstract. Web of Science does not have standardised subject indexing.

Depending on the subject or keyword field may be labelled : keywords / index terms / descriptors / controlled terms.

Step 1: Check what subject terms the database is using:

Step 2: Limit the search to those terms in the subject term field. In Scopus select Keywords from the drop down box.

Most databases also allow you to limit your search or refine your results set by:

• date
• language
• subject area
• geographical area
• material type (eg. Review articles, which will provide an overview of research on a particular topic)
• journal title

In many cases, you can also limit a search to scholarly or peer reviewed articles.

Notice terms that are bringing up irrelevant hits and try removing them.

For example, in the search:

(drug* or doping) and (athlet* or sport*) and (biomarker* or “biological marker*”)

The Scopus results show that the term drug is not being used for the concept of doping in sport, and by picking up the index term drug effects, is bringing up irrelevant papers such as:

The Effect of Green Tea and Sour Tea (Hibiscus sabdariffa L.) Supplementation on Oxidative Stress and Muscle Damage in Athletes

Consider including an additional AND statement to further refine your search.

If you find a good article for your topic, note the terms appearing in the database record (title, abstract, keyword) and consider if you can incorporate them into your search strategy using an additional AND.

For example, if the following search retrieved too many results:

drug* and (athlet* or sport*) and (biomarker* or “biological marker*”)

After reviewing the terms appearing in relevant articles, you might decide to narrow your search to:

doping and (athlet* or sport*) and (biomarker* or “biological marker*”) and (detect* or monitor* or test* or passport)

A final option for retrieving manageable results sets is to try breaking up your topic into several searches. The total number of results will be unchanged, but the results sets may be easier to review.

In the example:

( "climate change"  or  "global warming" )  and  ( grain*  or  cereal*  or  wheat  or  barley  or  rye)  and  ( crop* or  production ) and ( "weather event*"  or  thermal  or  rainfall or temperature  or drought )

You could try searching on rainfall or temperature etc., individually:

( "climate change"  or  "global warming" )  and  ( grain*  or  cereal*  or  wheat  or  barley  or  rye)  and  ( crop* or  production ) and rainfall

( "climate change"  or  "global warming" )  and  ( grain*  or  cereal*  or  wheat  or  barley  or  rye)  and  ( crop* or  production ) and temperature

Some databases (and Google) don’t require brackets but others, like Proquest, do. In Proquest a single line search without brackets such as:

doping and biomarker* or "biological marker*" and sport* or athlet* or cycl*

will retrieve over 17,000,000 results. This is because the database is retrieving at least three sets of results:

• the doping and biomarker* or "biological marker*" and sport* results
• the athlet* results - ie. all papers including only the term athlet*
• the cycl* results – all papers including a range of cycl* variations such as cyclists, cycling but also cycle