Since a literature review is an inevitable part of every thesis or dissertation every student or research scholar must be conscious of its nature, peculiarities and the common errors that may creep in a literature review. Some of these errors are easily rectifiable if only we know what a good literature review is.
A literature review is only a systematic written summary of all the available literature on a particular research subject. That is in fact a consolidated report of all the research findings unearthed by all those who have conducted research on the topic so far. Depending on the purpose for which we write the literature review, there may be crucial variations in the size and depth of the literature reviews we prepare at different times. It is in fact the purpose that determines the nature of the literature review. The literature review that forms part of a thesis or dissertation will be the most comprehensive and the longest as it is considered to be a serious academic activity that forms an essential component of the research itself. But if the literature review is to be attached to a research proposal, an application for a grant, or a scholarly article, it need not be very elaborate or long. So, first of all decide the scope, depth and length of the literature review you have to write.
The first stage in the preparation of a literature review is the collection of available literature on the topic. That will be the summary of all the research work that has been conducted on the subject so far. Decide how much of that you need. If it is a very common, old subject we will get sources from distant past. You must decide whether you will have to collect and write on all of it or need only recent ones. Sometimes you may find instructions limiting the literature to that of the last ten years and so on. If you miss that you will be losing much precious time. Also take care to see what kinds of sources you are permitted to use. Sometimes they may ask you to use only international journal articles or books. Lastly, ensure that your literature review conforms to the prescribed documentation style.