4 Recognising different types of information

At the simplest level, sources of information can be categorised into four main groups:

• Primary literature describes mainly new or ‘original’ material (e.g. a research paper published in peer-reviewed journals, or a patent).
• Secondary literature refers to material in which information that has appeared in another form is repackaged and disseminated more widely (e.g. review articles, academic textbooks and course materials).
• Grey literature is defined as ‘articles and information published, especially on the Internet, without a commercial purpose or the mediation of a commercial publisher’ (Dictionary of Information and Library Management, 2006). These include technical reports, government documents, working group documents etc.
• Personal communication is a potential source of information, often overlooked but becoming increasingly prevalent with the rise of social networking and online feeds (e.g. information from a colleague or expert opinion; online communication in a social networking site such as Twitter or Facebook; contributions to your own or other individual researchers, or group blogs and wikis).

Let’s take a closer look at some main forms of primary and secondary literature (research papers and review articles), and explore ‘grey’ literature in a little more detail.