Knowledge is cumulative: every piece of research will contribute another piece to it. That is why it is important to commence all research with a review of the related literature or research, and to determine whether any data sources exist already that can be brought to bear on the problem at hand. This is also referred to as secondary research. Just as each study relies on earlier work, it will provide a basis for future work by other researchers.
The literature review should provide the reader with an explanation of the theoretical rationale of the problem being studied as well as what research has already been done and how the findings relate to the problem at hand. In the paper "Not in my backyard: Toronto Resident Attitudes toward Permanent Charity Gaming Clubs", Classen presented the context of the current gaming situation, the Canadian and local gaming scene including theories as the acceptance of gaming and its future, as well as studies regarding the economic and social issues relating to gaming and how these affect residents’ opinions. It is most helpful to divide the literature into sub-topics for ease of reading.
The quality of the literature being reviewed must be carefully assessed. Not all published information is the result of good research design, or can be substantiated. Indeed, a critical assessment as to the appropriateness of the methodology employed can be part of the literature review, as Classen did with the Bradgate Study on Public Opinion.
This type of secondary research is also extremely helpful in exploratory research. It is an economical and often easily accessible source of background information that can shed light on the real scope of the problem or help familiarize the researcher with the situation and the concepts that require further study.