Science Thesis Writing Review Introductions

Review Paper -- Introductions

To understand Reviews as a kind of scientific publication, it helps to compare them to Research Reports,the type of publication with which we are most familiar.

       Reviews                                                     Reports
Evaluate current trends across         Contribute original experimental
a specific area of research                  evidence to a specific question
      Introduction                                         Introduction
      Review Topic 1                                        Method
      Review Topic 2                                        Results
      Review Topic 3 (etc.)                            Discussion
      Conclusion                                            (Conclusion, in some fields)

A research report explains the investigation and results of a single research question (or small set of highly-related questions). Research Reports are published in a format we are very familiar with, the IMRD, that plays nicely with an idealized version of the scientific method.

Research Reports Use IMRD to Manage Real Estate, Following an Idealized Scientific Method

A review paper is a different beast altogether. A Review paper looks at solely published reports to explain what is happening in an area of research as a whole. Review Articles make a different sort of contribution to science (McMillan, 2001, 3, emphasis added):

In contrast to research papers, conference presentations, and proposals, a review paper is a journal article that synthesizes work by many independent researchers on a particular subject or scientific problem. By bringing together the most pertinent findings of a large number of studies, a review paper serves as a valuable summary of research. Although it does not present the writer’s new discoveries, it does reflect his or her painstaking review of the literature in a defined field. Moreover, a good review not only summarizes information but also provides interpretative analysis and sometimes a historical perspective. Reviews may vary in aims, scope, length, and format, but they all include a relatively lengthy reference section. Journal editors sometimes invite prominent experts to write reviews of their particular fields, since the ability to give an audience an authoritative overview of a subject usually develops with experience. Whether solicited or unsolicited, review papers still must conform to journal specifications, and their author receive feedback from editors and reviewers before final publication.

In science, the review writer tries to understand what is happening across an area research, to discover patterns among the individual pieces of research that experimental researchers may or may not be aware of. Reviewers provide two very important and practical contributions to science. First, they do the hard work of all the reading required so that research results are regularly gathered in one place. Second, reviewers evaluate current research trends and make recommendations for where research and/or applications of research should be focused.

So, the Review Article has very different features from a research report. Professionally produced review articles have huge bibliographies, often 100 or more sources long. The task of the writer isn’t to answer a specific question using some kind of experimental method, but to take a step back and look at what is going on across many individual research projects. It’s one of those “forest and tree” situations: in a research report, the scientists are examining a tree; in a review paper, the scientist is looking at the forest.

Understanding and Writing Introductions

The introduction to a Review article has 5 steps. The most successful introductions have all 5 steps in the order presented below! This particular format accomplishes the two functional objectives of the introduction:

inform the reader about the topic;
persuade the reader that the author's perspective is valuable.

Topic -- a general statement of what the Review is about;
Signficance or Topic -- practical, clinical, or research signficance of topic;
Background of Problem -- a brief background framing the review, usually just a few sentences providing key definitions or concepts;
Gap -- what's missing in the literature (the motivation for the review);
Overview Statement -- usually has 2 parts
- Focus -- the critical perspective the reviewer is using to organize the body;
- Preview -- roadmap of body sections so that reader knows what's coming up.

Let's take a look at an example. The first image below identifies the article to be a review by examining the outline -- it consists of topical subheadings, so we know we are not reading experimental research. The images below this one show a typical Review Introduction in medicine. It is brief and leads the reader quickly to where the information in the paper happens: the body.