Literature Reviews

• Be selective. Include only studies that are relevant to your topic. 
• Organize the literature review around major topics of concepts. Use headings or topic sentences to communicate your organizational principle. 
• Synthesize and evaluate – don’t just summarize. 
• Use summary to help the reader relate each section to the larger topic and to make clear the movement of your argument. Where have we just been and where are we now going? 
• Tell a story about the research. Use this to guide your organization. 

Place background information (e.g., descriptions of a clinical situation or a theoretical model) at points where it will be most useful for readers. For example, if several researchers have used the same theoretical approach, describe that framework prior to reviewing those studies. 

Divide your review into sections with appropriate descriptors, following the guidelines of the documentation system you are using. Your outline provides the basis for this division because it has already grouped studies together under headings and subheadings. Note that you may want to cite a particular study in more than one section. 

End each section in your review with a summary sentence or paragraph. The length of summary should reflect the length of the section. End the entire review with a comprehensive summary that reiterates the most significant aspects and findings. This final summary (the “Discussion” section listed in your overview) is also the place to make major comparisons, offer your opinion or critique the adequacy of research approaches and methods, and point out critical inconsistencies. Your critique paves the way for you to close your review by posing unanswered questions, recommending approaches and variables for future research, and suggesting implications. If your review is a preface to your study, your critique should reinforce the rationale for conducting your research. You will then state your research question(s) and/or hypotheses. 

Suppose you’re planning to write a literature review regarding the effectiveness of short-term group therapy in reducing depression among nursing home residents. You have now collected research and made a list of the areas covered by your research: 

• Elderly people in nursing homes 
• Pharmacological treatment of depression 
• Use of psychotherapy among elderly people 
• Depression – causes, behavioral manifestations, effects 
• Measurement tools for depression 
• Societal attitudes toward aging 
• Psychological problems in elderly people 
• Depression in elderly people 
• Effects of group therapy 
• Side effects of drugs used to treat depression. 

Possible outline for the literature review: 

•  Depression in general (problem)
  •  Theories of causation 
  •  Behavioral manifestation 
  •  Effects 
•  Depression in elderly people, particularly in nursing homes (problem and its scope) 
•  Approaches other than therapy (previous work done) 
•  Effects of therapy on depression
  •  Long-term – disadvantages 
  •  Short-term 
  •  Group 

Notice that the outline proceeds from general to specific. As you move down the outline, you will deal with material in increasing depth, just as the relevance of the information to your own project increases. 

In the excerpts below, consider how the following affect readability: focus, sentence strength, citation placement, transition, and active vs. passive voice. 

Original

The relationship between motivation and the decision to acquire literacy has been studied by Smith (1975), Jones (1983), and Brown (1988). Motivation involves a number of expectations (Snappe, 1986; Krakel, 1988). A large study conducted by Amundson (1981) explored the beliefs of people entering literacy programs, specifically outcome expectations and self-efficacy despite obstacles. Paape (1979), and in a follow-up project Johnson (1985), studied resistance to motivational efforts or the tendency to ignore information about an issue that is difficult to acknowledge. A literacy promotion program needs to overcome the tendency to minimize the problem and to help people believe.

Revision

Research suggests that several factors influence an adult’s decision to acquire literacy. People need to be motivated to make such a decision (Smith, 1975; Jones, 1983; Brown, 1988). Motivation encompasses at least two categories of expectations (Snappe, 1986; Krakel, 1988). One must believe that literacy will affect one’s life positively (outcome expectations) and also that one can succeed in the effort to learn new skills (self-efficacy) despite obstacles (Amundson, 1981). Other research shows that when the problem is difficult to acknowledge, people tend to ignore information about it, i.e. to resist motivational efforts (Paape, 1979; Johnson, 1985). All these findings imply that a literacy promotion program needs to overcome the tendency to minimize the problem and to help people believe. 

Comparing these paragraphs should illustrate how certain rhetorical choices affect readability and clarity. Some guidelines: (1) Use headings and topic sentences to tell readers what the topic is and what point the material is contributing to the discussion. (2) Test sentences for relevance to the central point. (3) Don’t just point to the existence of literature on the topic; write about methods or results in the studies you discuss. (4) Place citations where they don’t interrupt or distract from the line of thought you’re presenting. (5) Use transitions. (6) Use strong, content laden, active verbs.

• Keep your tone objective as you summarize the research but don’t allow your objectivity to turn your review into an annotated bibliography (a laundry list). Rather, point out as you go along how studies relate to one another (e.g., “Smith (1988) and Jones (1990) used different samples to examine the same phenomenon”). 
• Be analytical; writing a review is an exercise in comparative thinking. Save your critique (opinions and judgments) for your final discussion, where they will be more effective and meaningful to the reader. 
• Link paragraphs to one another, and link studies within paragraphs. Make your review “reader friendly” by constructing the topic sentence of every paragraph so that it accomplishes two tasks: it “hooks” in some way to the previous paragraph and also announces what this new paragraph will be about (e.g., “In contrast to these studies, which have attempted to quantify the amount of stress an individual is subjected to, numerous researchers are now focusing on the individual’s perception of stressful life events”).
  • These connections may need to be made within a paragraph as well as among a group of paragraphs  (e.g., “Jones (1989) and Smith (1991) were among the first to examine the effects of childhood  abuse....Like Jones, Smith also used the State-Trait Inventory but included males in his sample” or “Lee’s  studies of learned helplessness support this study’s perspective of behavior modification as situation-specific”). 
• Use speculative language. Hypotheses are not proved; they are supported. Theories are not verified, but they may be tentatively accepted. Don’t make blanket generalizations. Use “may” rather than “will,” and modify your commentary with words such as “a majority of,” “to date,” and “appears to occur” because tomorrow’s findings may nullify today’s.
• Choose verbs that accurately describe what the research did; hypothesized, questioned, developed, implemented, measured, tested, and modified have quite different meanings. Avoid using “should” and “must”; they tend to sound preachy.
• Use direct quotations sparingly. They often take up more space than sentences constructed to summarize the original. Quotations may include concepts and vocabulary unfamiliar to the reader. 
• Avoid leisurely sentence openers: “This is indicative of the fact that” = “This indicates”, “The researchers came to the conclusion that” = “The researchers concluded”;
  • wordy phrases: “the area of education” = “in education”, “at this period of time” = “at this time”, “in an accurate manner” = “accurately”; and 
  • unnecessary modification: “exact replica,” “ultimate outcome,” “personal opinion”. 
• Use verb tenses appropriately. Use the past tense to summarize studies and procedures (e.g., “Danz measured four dimensions of self-efficacy...He modified two questionnaires”). Use the present perfect tense to suggest that something has occurred more than once in the past and may be continuing (e.g., “During the last two decades, researchers have often focused on the effects of posttraumatic stress disorder”). Use the present tense to describe theory and instruments (e.g., “Developmental tasks are central to Piaget’s theory”; “The STA uses a Likert scale to measure stress”), to discuss and critique (e.g., “The use of self-report has two major limitations”) and to generalize (e.g., “These findings suggest that adult learners prefer self-evaluation”). 
• Use the active and the passive voice appropriately. The active voice (“Cole replicated this test with four samples”) is less wordy and more dynamic than the passive voice (“This test was replicated with four samples by Cole”). However, it is effective to use the passive voice when the object is more important than the subject (e.g., “The children in group one were shown the videotape”); when the subject is unknown (“This phenomenon was first described according to eighteenth century standards”); when it would not be a good idea to identify the subject (“The first set of data was not accurately coded”); and when placing the object before the subject more clearly links into a previous sentence or paragraph (“...screen methods that enhance job satisfaction. These screening methods were also evaluated...”). Overuse of the passive voice suggests that research is occurring by itself and confuses the reader about who is doing what.