Systematic Reviews for the Social Sciences

Your systematic review will require you to use at least one bibliographic database to identify specific studies that meet the criteria for inclusion in your study. These databases require a more structured search strategy than using a basic search engine would. You will need to record your final search strategy in your protocol. 

To design your search strategy you need to:

Identify the key concepts in your research topic

Link them with OR/AND/NOT

Decide on Keywords to search for

Where required, find relevant Subject Headings (note: not all databases use subject headings)

Combining keyword and subject heading searches

We advise that you begin planning out your search strategy before you start searching any databases. You can then use this initial search strategy to perform your scoping searches, which will inform the search strategy you use in your systematic review and your choice of databases. 

Key concepts

The search should be structured around the key concepts being examined. Think about your research question - it may help you to refer back to the SPICE framework - think about your setting, population and intervention.

OR, AND, NOT

The commands OR, AND and NOT to instruct the database how to organise your searches.

Use OR to combine searches about the same concept - e.g. synonyms, related concepts, variant spellings, e.g. "young people" OR teenagers

Use AND to combine searches about different concepts, finding the overlap in research on these topics.

e.g. teenagers AND "social media"

Use NOT to exclude terms from your search. If you use NOT, an article containing the term you specify will be excluded from your results.

e.g: teenagers NOT children 

This can be useful, but use it with caution as you risk losing articles which may have been relevant. 

Keyword searching

Keyword searching is a style of searching where you find exact matches for your search terms within the titles, abstracts or keywords of journal articles. Here you are looking for terms used by the author(s), rather than the subject headings which are defined by the database. Keyword searching allows you to search for the exact terminology you want. However, you need to think of all the possible variations in terminology to avoid missing studies which are relevant to your topic. Think about synonyms, related terms and spelling variations (particularly UK/US).

• Example: If your population is "young people," this is likely to be a key concept in your research, so consider the other ways this group may be described like young person, teen, adolescent etc...

Keyword searching tips

There are tools you can use to help with keyword searching. Different databases may use some variations on these tools, so check what is available in the database you are searching by consulting the Library’s Quick Guides or by checking the database’s help pages. 

Most databases allow you to use the asterisk to expand on the stem of a word - this is known as truncation:

• e.g. teen* would find references to teen, teens, teenage, teenager, teenagers, teenaged...

Some of your keywords may actually be "key phrases" - ie: more than one word. If you put them into speechmarks, you instruct the database that you want to retrieve records containing these words next to each other in this order. 

• eg: "young person" rather than young person - which would find you results where the words young and person could appear unrelated to each other!

Some databases may allow proximity searches – finding certain words that occur near each other. This is a bit like a phrase search, but more flexible. The instructions for this usually vary between databases, so check the help pages for the database you want to use. 

• eg: teen NEAR/3 girl will find records where teen appears within 3 words of girl

Most databases support a wildcard which can help with spelling variations. It is often &, $ or ?, but again, you will want to check which one your chosen database uses. 

• eg: wom$n will search for woman and women

You can combine these tools - speechmarks, truncation and wildcards - to begin building your search strategy. So your keyword search for young people may start to look like this:

• "young people" OR "young person" OR teen* OR adoles* OR "young wom$n" OR "young m$n"

Using Subject Headings

Some databases (eg: Medline, PsycINFO and Embase) use subject headings to make it easier to find articles on a specific subject. Each article listed in the database is assigned a number of subject headings which represent what the article covers. The advantage of subject headings is that all of the articles on the same subject will be given the same subject heading regardless of the terminology used by the individual authors. This makes it easier to cover all the variations in terms and offers a precise method of searching. However, they can take time to catch up with new developments. Indexers occasionally make mistakes.

• EG: in PsycINFO papers about teenagers will all be assigned the subject heading adolescent regardless of whether the author has used terms such as ‘young people’, ‘teenager’, 'emerging adults’ and so on.

Combining searches

You can combine subject heading and keyword searches.

If you are doing a quick search, you only need to use one of these search methods (and some databases will only support keyword searching!) But, if the database allows and you want to retrieve as much as you can on your topic, you should use both methods. This overcomes the limits of both approaches.

Next step: Scoping searches