Psychology

Why search grey literature?

Grey literature is an important source of information when conducting a large-scale review. It includes a wide range of documents not produced by commercial publisher's. This does mean that it can be difficult to systematically search for relevant evidence, however, public health research may only be available via these sources.

If you are struggling to find sources cited in a piece of grey literature, it may be available via interlibrary requests, via an institutional repository or you may need to contact the author directly. Get in touch with us on the chat box below if you and we can help with locating sources.

How to evaluate content?

Take the same approach you would to evaluate any content you find online. Unlike commercially published sources, grey literature does not go through the same level of scrutiny as an article in a peer-reviewed journal would.

The questions you can use to evaluate sources are:

Who? 

Who is the author(s) What are their credentials? Are they an expert in their field? (use Google Scholar as quick check to see if they’ve been cited by others) If there isn’t an author then look at the organisations “mission statement” or “about us” page to access their impartiality.

What? 

What information is being given? Is it opinion, commentary, or factual? Does the item have a detailed reference list or bibliography?

Where? 

Where is the information coming from? Check the website domain. Secure websites often begin with https://

Remember that links for grey literature, unless found in an institutional repository, may not be maintained, so when you find it, save it.  

.co.uk – UK commercial and general

.ac.uk – UK academic institutions (Universities, Colleges, Research establishments)

.gov.uk - UK government (including local)

.edu – U.S. educational institutions such as Universities

.org –organisations (often non-profit but not always

When? 

When was the information written or published – is it up-to-date? (Sources with no date information should be treated with caution) When was the website last updated? Check the bibliography for relevant contemporary material?

Text? 

Is the text well-written? Are their spelling or grammatical errors? Is the language emotive? Does the work seem to be balanced in presentation? Is the author’s standpoint clear? Are any limits clearly stated? Is it clear where the data came from? A useful article and checklist can be found here.

Using Search Engines: Search Tips for improving results

You can also use search engines effectively to search for Grey Literature. Try using Google Advanced search or DuckDuckGo

New Projects

If you are starting a new research project then try clearing your browsing data before you start to avoid your previous searches influences your results. Not only will this help you get to the results you want, but will help reduce the effects of the filter bubble. Also worth logging out of user accounts; try incognito mode; not 100% effective.

Reproducible?

It's important to remember that most search engines will automatically look for synonyms and variations of your keywords and will exclude results if there are too few results. This is a helpful aspect of search engines, however, you are unable to control the searches, making them not reproducible by others.

Search Commands

Use search commands, filters or advanced search functions to get back the results you want and avoid information overload. Search command AND is often assumed. (See the Search Commands tab for details).