Literature Review**

A literature review must do these things:

1. be organized around and related directly to the thesis or research question you are developing
2. synthesize results into a summary of what is and is not known
3. identify areas of controversy in the literature
4. formulate questions that need further research

Ask yourself questions like these about each book or article you include:

1. Has the author formulated a problem/issue?
2. Is it clearly defined? Is its significance (scope, severity, relevance) clearly established?
3. Could the problem have been approached more effectively from another perspective?
4. What is the author's research orientation (e.g., interpretive, critical science, combination)?
5. What is the author's theoretical framework (e.g., psychological, developmental, feminist)?
6. What is the relationship between the theoretical and research perspectives?
7. Has the author evaluated the literature relevant to the problem/issue? Does the author include literature taking positions she or he does not agree with?
8. In a research study, how good are the basic components of the study design (e.g., population, intervention, outcome)? How accurate and valid are the measurements? Is the analysis of the data accurate and relevant to the research question? Are the conclusions validly based upon the data and analysis?
9. In material written for a popular readership, does the author use appeals to emotion, one-sided examples, or rhetorically-charged language and tone? Is there an objective basis to the reasoning, or is the author merely "proving" what he or she already believes?
10. How does the author structure the argument? Can you "deconstruct" the flow of the argument to see whether or where it breaks down logically (e.g., in establishing cause-effect relationships)?
11. In what ways does this book or article contribute to our understanding of the problem under study, and in what ways is it useful for practice? What are the strengths and limitations?
12. How does this book or article relate to the specific thesis or question I am developing?

Here are some of the questions your literature review should answer:

1. What do we already know in the immediate area concerned?

2. What are the characteristics of the key concepts or the main factors or variables?

3. What are the relationships between these key concepts, factors or variables?

4. What are the existing theories?

5. Where are the inconsistencies or other shortcomings in our knowledge and understanding?

6. What views need to be (further) tested?

7. What evidence is lacking, inconclusive, contradictory or too limited?

8. Why study (further) the research problem?

9. What contribution can the present study be expected to make?

10. What research designs or methods seem unsatisfactory

How Can I Write A Good Literature Review?

Remember the purpose: it should answer the questions we looked at above. Look at how published writers review the literature. You'll see that you should use the literature to explain your research - after all, you are not writing a literature review just to tell your reader what other researchers have done. You aim should be to show why your research needs to be carried out, how you came to choose certain methodologies or theories to work with, how your work adds to the research already carried out, etc.

Read with a purpose: you need to summarize the work you read but you must also decide which ideas or information are important to your research (so you can emphasize them), and which are less important and can be covered briefly or left out of your review. You should also look for the major concepts, conclusions, theories, arguments etc. that underlie the work, and look for similarities and differences with closely related work. This is difficult when you first start reading, but should become easier the more you read in your area.

Write with a purpose: your aim should be to evaluate and show relationships between the work already done (Is Researcher Y's theory more convincing than Researcher X's? Did Researcher X build on the work of Researcher Y?) and between this work and your own. In order to do this effectively you should carefully plan how you are going to organize your work.

*A lot of people like to organize their work chronologically (using time as their organizing system). Unless developments over time are crucial to explain the context of your research problem, using a chronological system will not be an effective way to organize your work. Some people choose to organize their work alphabetically by author name: this system will not allow you to show the relationships between the work of different researchers, and your work, and should be avoided! Instead, organize the literature review into sections that present themes or identify trends, including relevant theory. You are not trying to list all the material published, but to synthesize and evaluate it according to the guiding concept of your thesis or research question.

TRAPS

Some traps to avoid:

Trying to read everything! As you might already have discovered, if you try to be comprehensive you will never be able to finish the reading! The idea of the literature review is not to provide a summary of all the published work that relates to your research, but a survey of the most relevant and significant work.

Reading but not writing! It's easier to read than to write: given the choice, most of us would rather sit down with a cup of coffee and read yet another article instead of putting ourselves in front of the computer to write about what we have already read! Writing takes much more effort, doesn't it? However, writing can help you to understand and find relationships between the work you've read, so don't put writing off until you've "finished" reading - after all, you will probably still be doing some reading all the way through to the end of your research project. Also, don't think of what you first write as being the final or near-final version. Writing is a way of thinking, so allow yourself to write as many drafts as you need, changing your ideas and information as you learn more about the context of your research problem.

Not keeping bibliographic information! The moment will come when you have to write your references page . . . and then you realize you have forgotten to keep the information you need, and that you never got around to putting references into your work. The only solution is to spend a lot of time in the library tracking down all those sources that you read, and going through your writing to find which information came from which source. To avoid this nightmare, always keep this information in your notes. Always put references into your writing.

Literature Review: An Example

Here is an example of using the literature to explain and define a problem. This example is taken from an introduction because most thesis literature reviews tend to be too long for us to easily look at. Although your literature review will probably be much longer than the one below, it is useful to look at the principles the writers have used.

On the optimal container size in automated warehouses

Y. Roll, M.J. Rosenblatt and D. Kadosh, Proceedings of the Ninth ICPR

Automated storage and retrieval systems (AS/RS) are being introduced into the industry and warehousing at an increasing rate. Forecasts indicate that this trend will continue for the foreseeable future (see [1]). Research in the area of AS/RS has followed several avenues.  Early work by Hausman, Schwarz and Graves [6, 7] was concerned with storage assignment and interleaving policies, based on turnover rates of the various items. Elsayed [3] and Elsayed and Stern [4] compared algorithms for handling orders in AR/RS. Additional work by Karasawa et al. [9], Azadivar [2] and Parry et al. [11] deals with the design of an AS/RS and the determination of its throughput by simulation and optimization techniques.

Several researchers addressed the problem of the optimal handling unit (pallet or container) size, to be used in material handling and warehousing systems. Steudell [13], Tanchoco and Agee[14], Tanchoco et al. [15] and Grasso and Tanchoco [5] studied various aspects of this subject. The last two references incorporate the size of the pallet, or unit load, in evaluation of the optimal lot sizes for multi-inventory systems with limited storage space. In a report on a specific case, Normandin [10] has demonstrated that using the 'best-size' container can result in considerable savings. A simulation model combining container size and warehouse capacity considerations, in an AS/RS environment, was developed by Kadosh [8]. The general results, reflecting the stochastic nature of the flow of goods, are similar to those reported by Rosenblatt and Roll [12]. Nevertheless, container size was found to affect strongly overall warehousing costs.

In this paper, we present an analytical framework for approximating the optimal size of a warehouse container.  The approximation is based on series of generalizations and specific assumptions.  However, these are valid for a wide range of real life situations. The underlying assumptions of the model are presented in the following section.

Notice how the writers have:

grouped similar information: "Steudell [13], Tanchoco and Agee[14], Tanchoco et al. [15] and Grasso and Tanchoco [5] studied various aspects of this subject."

shown the relationship between the work of different researchers, showing similarities/differences: "The general results, reflecting the stochastic nature of the flow of goods, are similar to those reported by Rosenblatt and Roll [12]."

indicated the position of the work in the research area history: "Early work by Hausman, Schwarz and Graves [6, 7]  .  .  .  "

moved from a general discussion of the research in AS/RS to the more specific area (optimal container size) that they themselves are researching i.e. they relate previous work to their own to define it, justify it and explain it.

**This document is complied, modified, and expanded from several sources.