In order to synthesize, you must blend knowledge from numerous sources and add your own analysis of the material. This implies that each of your paragraphs will contain a variety of sources and citations, as well as your own thoughts and perspective. A synthesis is thus an integration of ideas and information from various parts of the text. Citations are important in any type of paper, but they are especially important in a research paper because everything you cite needs to be relevant to the topic at hand. If you use information from a study that was done years ago for example, then you should explain why it is relevant today. You would not want to claim that modern studies show x to be true when in fact they show y to be true. It is also important to note that citations are not just words on a page. They are references to other pieces of evidence, often outside of books. For example, if you were doing research on cancer and discovered something interesting about fruit flies, you could look up this new information in several different reference books and journals, which would be examples of citations. Finally, a synthesis is not just the collection of facts from multiple sources. It is also their interpretation through your own eyes. While collecting information may give you some idea about the topic, thinking about it critically and drawing conclusions based on what you have found can help shape your understanding of it greatly.