How to Write a Literature Review

How to Write a Literature Review A literature review paper is not an original publication. On occasion, a literature review will contain new data (from the authors own laboratory) that have not yet appeared in a primary journal. However, the purpose of literature review paper is to review previously published literature and to put it into some kind of perspective. A literature review paper is usually long, typically ranging between 10 and 50 printed pages. (Some journals now print short minireviews.) The subject is fairly general, compared with that of research papers. And the literature review is, of course, the principal product. However, the really good literature review papers are much more than annotated bibliographies. They offer critical evaluation of the published literature and often provide important conclusions based on that literature. The organization of a literature review paper is usually different from that of a research paper. Obviously, the Materials and Methods, Results, Discussion arrangement cannot readily be used for the literature review paper. Actually, some literature review articles are prepared more or less in the IMRAD format; for example, they may contain a Methods section describing how the literature review was done. If you have previously written research papers and are now about to write your first literature review, it might help you conceptually if you visualize the review paper as a research paper, as follows. Greatly expand the Introduction; delete the Materials and Methods (unless original data are being presented); delete the Results; and expand the Discussion. Actually, you have already written many literature review papers. In format, a literature review paper is not very different from a well-organized term paper or thesis. As in a research paper, however, it is the organization of the review paper that is important. The writing will almost take care of itself if you can get the thing organized. PREPARING AN OUTLINE Unlike research papers, there is no prescribed organization for literature review papers. Therefore, you will have to develop your own. The cardinal rule for writing a literature review paper is prepare an outline. The outline must be prepared carefully. The outline will assist you in organizing your paper, which is all-important. If your literature review is organized properly, the overall scope of the review will be well defined and the integral parts will fit together in logical order. Obviously, you must prepare the outline before you start writing. Moreover, before you start writing, it is wise to determine whether a literature review journal (or primary journal that also publishes review articles) would be interested in such a manuscript. Possibly, the editor will want to limit or expand the scope of your proposed literature review or to add or delete certain of the subtopics. The Instructions to Authors in Microbiology and Molecular Biology Reviews says it this way: . . . an annotated topical outline . . . will be evaluated by the editors, and if the material is satisfactory, the authors will be invited to write the literature review. Not only is the outline essential for the preparer of the literature review, it is also very useful to potential readers of the review. For that reason, many review journals print the outline at the beginning of the article, where it serves as a convenient table of contents for prospective readers. TYPES OF REVIEWS Before actually writing a review, you also need to determine the critical requirements of the journal to which you plan to submit the manuscript. Some journals demand critical evaluation of the literature, whereas others are more concerned with bibliographic completeness. There are also matters of organization, style, and emphasis that you should have in mind before you proceed very far. By and large, the old-line literature review journals prefer, and some demand, authoritative and critical evaluations of the published literature on a subject. Many of the book series (Annual Review of, Recent Advances in, Yearbook of, etc.), however, publish literature reviews designed to compile and to annotate but not necessarily to evaluate the papers published on a particular subject during a defined time period. Some active areas of research are reviewed yearly. Both of these types of literature review papers serve a purpose, but the different purposes need to be recognized. At one time, literature review papers tended to present historical analyses. In fact, the reviews were often organized in chronological order. Although this type of review is now less common, one should not deduce that the history of science has become less important. There is still a place for history. Today, however, most review media prefer either state of the art reviews or reviews that provide a new understanding of a rapidly moving field. Only the recent literature on the subject is catalogued or evaluated. If you are reviewing a subject that has not previously been reviewed or one in which misunderstandings or polemics have developed, a bit more coverage of the historical foundations would be appropriate. If the subject has been effectively reviewed before, the starting point for your literature review might well be the date of the previous review (not publication date, but the actual date up to which the literature has been reviewed). And, of course, your literature review paper should start out by citing the previous review. WRITING FOR THE AUDIENCE Another basic difference between literature review papers and primary papers is the audience. The primary paper is highly specialized, and so is its audience (peers of the author). The literature review paper will probably cover a number of these highly specialized subjects, so that the review will be read by many peers. The literature review paper will also be read by many people in related fields, because the reading of good reviews is the best way to keep up in ones broad areas of interest. Finally, literature review papers are valuable in the teaching process, so that student use is likely to be high. (For these reasons, by the way, order plenty of reprints of any review paper you publish, because you are likely to be inundated with reprint requests.) Because the literature review paper is likely to have a wide and varied audience, your style of writing should be much more general than it need be for a research paper. Jargon and specialized abbreviations must be eliminated or carefully explained. Your writing style should be expansive rather than telegraphic. IMPORTANCE OF INTRODUCTORY PARAGRAPHS Readers are much influenced by the Introduction of a literature review paper. They are likely to decide whether or not to read further on the basis of what they find in the first few paragraphs (if they havent already been repelled by the title). Readers are also influenced by the first paragraph of each major section of a literature review, deciding whether to read, skim, or skip the rest of the section depending on what they find in the first paragraph. If first paragraphs are well written, all readers, including the skimmers and skippers, will be able to achieve some degree of comprehension of the subject. IMPORTANCE OF CONCLUSIONS Because the literature review paper covers a wide subject for a wide audience, a form of conclusions is a good component to take the trouble to write. This is especially important for a highly technical, advanced, or obscure subject. Painful compromises must sometimes be made, if one really tries to summarize a difficult subject to the satisfaction of both expert and amateur. Yet, good summaries and simplifications will in time find their way into textbooks and mean a great deal to students yet to come.