Grey Literature: How do I evaluate Grey Literature?

Just like any other source, information from grey literature needs to be critically evaluated to determine the quality of the information, and the relevance to your research. This is particularly important as grey literature has not usually received the same quality checking as peer reviewed published material. However it may still be reliable information for your research, and important to include to minimise any bias in your research

Grey literature should ideally be appraised to the same standards as those used to evaluate any other literature. The information and activities on evaluating information sources provides excellent information and guidance on how to evaluate all your sources, grey or not.

Grey literature can be difficult to find and access

• Limited number of copies may have been produced 
• Distribution can be limited
• It is not always archived
• It is not always indexed
• It is not always published online
• The storage format for older materials may require obsolete technology for access

The quality of grey literature is variable

• It is not necessarily subjected to a formal peer review process
• Materials are essentially self-published, e.g. a white paper is made publicly available by the government department the authors are employed in.