If you're writing a Master's dissertation, your literature review should be between 2 and 3,000 words long, depending on a variety of circumstances. Consult your boss! If you're writing an undergraduate dissertation, your literature review will most likely be 2,000 words long, but the same idea applies: ask! Consult your advisor! The purpose of the literature review is to summarize what has been previously published on your topic. You should not claim new information or make new claims based on the results of your search. Rather, you should describe the findings of previous research in your field of interest and explain how they relate to your own goals for the project. A good literature review will also help readers understand why your project is important and relevant. In order to achieve these goals, a good literature review needs to be comprehensive. This means that you need to search for all relevant studies, not just those that support your own position. In addition, you should try to find out more about studies that were not included in the original analysis or discussion of the data because they weren't known at the time. This helps other researchers later come across interesting studies that might otherwise have gone unnoticed. Finally, a good literature review requires you to be clear in your language and presentation. For example, if you are using statistics to analyze data, then you should include a statistical method section with clarity in its language. Also, avoid using jargon when discussing topics outside of your area of expertise!