A literature search is a "systematic and thorough search of all types of published literature in order to identify as many items as possible that are relevant to a particular topic." (Gash, S., 2000).
Reasons for searching the literature according to Hart (2001):
1. to identify work already done or in progress that is relevant to your work;
2. to help to prevent you from duplicating what has already been done;
3. to avoid some of the pitfalls and errors of previous research;
4. to help you design the methodology for your project by identifying the key issues and data collection techniques best suited to your topic;
5. to enable you to find gaps in existing research, thereby giving you a unique topic.
Gash, S. (2000). Effective literature searching for research. (2nd ed.). Aldershot, Hampshire: Gower
Hart, C. (2001). Doing a literature search:a comprehensive guide for the social sciences. London:Sage