Documentary research is the use of outside sources, documents, to support the viewpoint or argument of an academic work. The process of documentary research often involves some or all of conceptualising, using and assessing documents. The analysis of the documents in documentary research would be either quantitative or qualitative analysis (or both). The key issues surrounding types of documents and our ability to use them as reliable sources of evidence on the social world must be considered by all who use documents in their research. 
Type of documents
Examples of documents include government publications, newspapers, certificates, census publications, film and video, paintings, personal photographs, diaries and other written, visual and pictorial sources in paper, electronic, or other `hard copy' form. Along with surveys and ethnography, documentary research is one of the three major types of social research and arguably has been the most widely used of the three throughout the history of sociology and other social sciences. It has been the principal method for leading sociologists.
- Balihar, Sanghera, Qualitative research methods: documentary research. From the internet, October 1st, 2007 http://uk.geocities.com/balihar_sanghera/qrmdocumentaryresearch.html Wayback Machine Nov 2007
- Scott, J. 2006, "Documentary Research" London, Sage Publications Ltd. ISBN 978-1-4129-0817-7
- Prior, L. 2003, "Using Documents in Social Research". London, Sage.