Educational Research On-Line
Literature Review: Why conduct one?
For researchers conducting literature reviews, the benefits of the literature review include, but are not limited to, the following.
Searching through the literature on a given topic enables one to determine what has already been done. With this knowledge, the researcher can better frame his or her study to build on prior research and expand knowledge on the given topic.
The literature review may also prove helpful in designing and executing the study. Sometimes researchers, for example, may have difficulty determine the best method for measuring a construct. For instance, suppose one wished to measure reading interest in first grade students. It should be obvious that with students of this age, instruments designed for high school or college students will be inappropriate due to the complexity of the phrasing found in each item. With a proper literature review, one may find a suitable instruments for first grade students. This instrument would probably incorporate easy to understand pictures rather than text as response sets thus enabling young children respond to visual cues.
Besides measurement issues, researchers may face difficulties in determining how best to implement a given treatment in an experiment, how best to analyze a complex set of data, or how best to interpret outcomes of the study that do not fit a predicted pattern. The issues can often be resolved with a thorough literature review.
Another and more important benefit of a thorough literature review is that it facilitates discovery of theoretical linkages among variables and ideas that may not have been considered previously by the researcher, and it provides insight that helps the researcher to make recommendations for future research. From my own experience I can recall numerous occasions where a seemingly unconnected study I was reading provided insight into connections among constructs that I had not known or imagined. The following example helps to illustrate this point.
In an experiment on student evaluations of instruction, I found that if I requested that students evaluate me several times during the academic term, my end-of-term evaluations would be higher from these students than from students in a control class. I found this somewhat surprising since I typically made little to no changes in either my experimental or control class. However, I would review the evaluations with my experimental class and sometimes make minor adjustments to classroom procedures as a result of those evaluations. However, any change I made in the experimental class I also made in the control class.
The question I faced was why would students in my experimental class, who are getting no better instruction than students in the control class, rate me higher on end-of-term evaluations just because they were asked to evaluate me several times during the term? Shortly after noting this question, I read an article that showed that perceived autonomy in the classroom may affect student motivation and performance (Garcia & Pintrich, 1996). How is this related to my study? Well, students in the experimental class were aware of any small changes I made while students in the control may not have noticed the change. Further, just by asking my experimental classes to offer suggestions for improvement (a topic addressed in the evaluation form), they may have felt empowered in the class; they may have thought they had some autonomy in the class. Perhaps this perceived autonomy led to my higher evaluations.
By noting the findings of Garcia and Pintrich (1996), I was able to provide a better and more theoretically oriented explanation of my findings. In addition, I could suggest that future research examine the possible association between autonomy, both real and perceived, and student evaluations.
Literature Review: Why read one?
From a reader's perspective, the literature review is a story that explains the background to the problem the researcher (the writer) is exploring, and makes clear why this problem holds either theoretical or practical significance. The literature review sets the context of the research problem for the reader. From the literature review, the reader should understand why the particular research questions or hypotheses are addressed in the study, and how these research questions or hypotheses will expand knowledge in the given area. In short, the literature review enables the reader to understand why research questions or hypotheses were formulated, and presents the reader with background knowledge to understand better the studys purpose or the importance of the study.
Characteristics of Well Written Literature Reviews
- Primary vs. secondary citations: A primary source of a citation is a study in which the author(s) are the ones who collected and analyzed the data or developed the idea, hypothesis, or theory. A secondary source is one that is removed from the primary author. For example, secondary sources often include general reviews of research in a given topic (like meta-analyses), general summaries of research (like encyclopedia entries), or one paraphrasing or quoting another's work. It is best to use primary sources for citations simply because the primary author is less likely explain or report inaccurately his or her own work.
- Empirical research based citations: Empirical studies are those in which the authors collected data to address a question. Non-empirical sources include essays or position papers (author explains stance on something but without supporting data), theoretical papers, and non-empirical literature reviews. A meta-analysis would typically be considered an empirical source for a citation. One easy method for determining whether a given source is empirical is to determine whether data were collected and presented. If, for example, there is a Methods section to the paper (with subsections for Participants, Procedures, etc.), then that source is most likely empirical.
- Recency of citations: To provide as complete picture of the current state of research in a given topic, it is necessary to ensure that citations cover a wide range of time periods. Most writers focus on the most recent research when creating a literature review. Unfortunately, many tend to exclude older research, especially research published in the 1920, 30, 40, 50, and 60's. Surprising to many, researchers during these decades often sought answers to the same questions addressed today.
- Agreement between citations and reference section: This characteristic appears to be relatively unimportant when consider against the other characteristics of a good literature review, but it is important. It is not uncommon to find a published study that fails to include in the reference section all sources cited, and this can be quite frustrating to a researcher interested in finding the cited source.
Example (this example paragraph would follow the literature review):
As noted above, both educators and educational researchers argue that minimum competency testing will result in more students dropping out of school. In addition, academically at-risk students and racial minorities are expected to be especially affected by poor performances on competency tests. In this study we will attempt to provide empirical evidence to answer the following questions about the relation between competency test performance and dropping out of high school: (a) Do students who fail the minimum competency test show an increased likelihood of dropping out of school? (b) Are students with lower achievement records more likely to leave school if they fail the competency test than students with average and above average achievement records? (c) Are Black and Hispanic students differentially affected, in terms of dropping out, by failure on the competency relative to White students? This study, unlike other published work on increased standards, will provide an empirical analysis of the relationship between test performance and dropping out of high school. In addition, this study extends research by specifically examining testing performance for academically at-risk students and racial minority students and their decisions to leave school.
Garcia, T., & Pintrich, P.R. (1996). The effects of autonomy on motivation and performance in the college classroom. Contemporary Educational Psychology, 21, 477-486.