|
Journal
articles: these are good especially for up-to-date information. Bear in mind,
though, that it can take up to two years to publish articles. They are frequently used in
literature reviews because they offer a relatively concise, up-to-date format for
research, and because all reputable journals are refereed (i.e. editors publish only
the most relevant and reliable research).
Books: books
tend to be less up-to-date as it takes longer for a book to be published than for a
journal article. Text books are unlikely to be useful for including in your literature
review as they are intended for teaching, not for research, but they do offer a good
starting point from which to find more detailed sources.
|
 |
|
Conference
proceedings: these can be useful in providing the latest research, or research
that has not been published. They are also helpful in providing information on which
people are currently involved in which research areas, and so can be helpful in tracking
down other work by the same researchers.
Government/corporate
reports: many government departments and corporations commission or carry out
research. Their published findings can provide a useful source of information, depending
on your field of study.
Newspapers:
since newspapers are generally intended for a general (not specialized) audience, the
information they provide will be of very limited use for your literature review. Often
newspapers are more helpful as providers of information about recent trends, discoveries
or changes, e.g. announcing changes in government policy, but you should then search for
more detailed information in other
sources.
Theses
and dissertations: these can be useful sources of information. However there are
disadvantages: 1) they can be difficult to obtain since they are not published, but are
generally only available from the library shelf or through interlibrary loan; 2) the
student who carried out the research may not be an experienced researcher and therefore
you might have to treat their findings with more caution than published research.
|
|
|
Internet:
the fastest-growing source of information is on the Internet. It is impossible to
characterize the information available but here are some hints about using electronic
sources: 1) bear in mind that anyone can post information on the Internet so the quality
may not be reliable, 2) the information you find may be intended for a general audience
and so not be suitable for inclusion in your literature review (information for a general
audience is usually less detailed) and 3) more and more refereed electronic journals
(e-journals) are appearing on the Internet - if they are refereed it means that there is an
editorial board that evaluates the work before publishing it in their e-journal, so the
quality should be more reliable (depending on the reputation of the journal).
CD-ROMS:
at the moment, few CR-ROMs provide the kind of specialized, detailed information about
academic research that you need for your own research since most are intended for a
general audience. However, more and more bibliographies are being put onto CD-ROM
for use in academic libraries, so they can be a very valuable tool in searching for the
information you need.
|
|
| Magazines:
magazines intended for a general audience (e.g. Time) are unlikely to be useful in
providing the sort of information you need. Specialized magazines may be more useful (for
example business magazines for management students) but usually magazines are not useful
for your research except as a starting point by providing news or general information
about new discoveries, policies, etc. that you can further research in more specialized
sources. |
|
WHY WRITE A REVIEW OF THE LITERATURE?
The literature review is a critical
look at the existing research that is significant to the work that you are carrying out.
Some people think that it is a summary: this is not true. Although you need to
summarize relevant research, it is also vital that you evaluate this work, show the
relationships between different work, and show how it relates to your work.
In other words, you cannot simply give a concise description of, for example, an article:
you need to select what parts of the research to discuss (e.g. the methodology), show how
it relates to the other work (e.g. What other methodologies have been used? How are they
similar? How are they different?) and show how it relates to your work (what is its
relationship to your methodology?).
Keep in mind that the literature
review should provide the context for your research by looking at what work has
already been done in your research area. It is not supposed to be just a summary of other
people's work!
|
Here are
some of the questions your literature review should answer:
-
What do we already know in the
immediate area concerned?
-
What are the characteristics of
the key concepts or the main factors or variables?
-
What are the relationships
between these key concepts, factors or variables?
-
What are the existing theories?
-
Where are the inconsistencies or
other shortcomings in our knowledge and understanding?
-
What views need to be (further)
tested?
-
What evidence is lacking,
inconclusive, contradictory or too limited?
-
Why study (further) the research
problem?
-
What contribution can the
present study be expected to make?
-
What research designs or
methods seem unsatisfactory?
|
|
WRITING YOUR OWN LITERATURE REVIEW
It's easy to write a bad literature
review and difficult to write a good one. The main mistake that a lot of people make is to
write a literature review that looks like this:
II LITERATURE
REVIEW
Until recently many researchers
have shown interest in the field of coastal erosion and the resulting beach profiles. They
have carried out numerous laboratory experiments and field observations to illuminate the
darkness of this field. Their findings and suggestions are reviewed here.
JACHOWSKI (1964) developed a
model investigation conducted on the interlocking precast concrete block seawall. After a
result of a survey of damages caused by the severe storm at the coast of USA, a new and
especially shaped concrete block was developed for use in shore protection. This block was
designed to be used in a revetment type seawall that would be both durable and economical
as well as reduce wave run-up and overtopping, and scour at its base or toe. It was proved
that effective shore protection could be designed utilizing these units.
HOM-MA and HORIKAWA (1964)
studied waves forces acting on the seawall which was located inside the surf zone. On the
basis of the experimental results conducted to measure waves forces against a vertical
wall, the authors proposed an empirical formula of wave pressure distribution on a
seawall. The computed results obtained by using the above formula were compared well with
the field data of wave pressure on a vertical wall.
SELEZOV and ZHELEZNYAK (1965)
conducted experiments on scour of sea bottom in front of harbor seawalls, basing on the
theoretical investigation of solitary wave interaction with a vertical wall using
Boussinesque type equation. It showed that the numerical results were in reasonable
agreement with laboratory experimental data.
and so on.
Have another look at the questions a literature review should answer (the
arrow will bring you back here). See if you can answer the following questions about
the literature review above:
Click on the questions to find the
answers.
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!
For more information about writing,
access The Basics of Good Writing.
When you read for your literature
review, you are actually doing two things at the same time (which makes things more
difficult for you!):
- you are trying to define your
research problem: finding a gap, asking a question, continuing previous research,
counter-claiming (see the introductions
page);
- you are trying to read every
source relevant to your research problem.
Naturally, until you have defined
your problem, you will find that there are hundreds of sources that seem relevant.
However, you cannot define your problem until you read around your research area. This
seems a vicious circle, but what should happen is that as you read you define your
problem, and as you define your problem you will more easily be able to decide what
to read and what to ignore.
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. If you're lucky, maybe you can actually do this
before your defence - more likely, you will unable to find all your sources, a big headache
for you and your committee. To avoid this nightmare, always keep this information in your
notes. Always put references into your writing. Notice how on this course we have
referenced the works that we have referred to - you should do the same. (Access our How to Reference page for more
information about why and how to do reference). |
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. |
HERE IS AN OUTLINE OF THE SAME PIECE OF WRITING
On the optimal container size in
automated warehouses
Y. Roll, M.J. Rosenblatt and D. Kadosh, Proceedings of the Ninth ICPR
1. Forecasts of increasing rate of
AR/RS introduction [1]
2. Storage assignment/interleaving
policies (Hausman, Schwarz, Graves [6,7])
3. Comparison of algorithms for
handling orders (Elsayed [3], Elsayed & Stern [4])
4. Design of AS/RS &
determination of throughput (Karasawa et al. [9], Azadivar [2], Parry et al. [11])
5. Optimal handling unit (Steudel
[13], Tanchoco & Agee [14])
a. with pallet size/unit load
(Tanchoco et al. [15], Grasso & Tanchoco [5])
b. “best-size” gives
savings (Normandin [10])
c. simulation model (Kadosh [8])
d. stochastic flow (Kadosh [8],
Rosenblatt and Roll [12])
6. Summary of previous research:
“container size was found to affect strongly overall warehousing costs.”
7. Present research: “an
analytical framework for approximating the optimal size of a warehouse container.”
From this outline, it is clear that
the writers are organizing their information around ideas (in this case research)
not around the researchers. This enables them to focus on the research itself, to
show how different research is related, and how it all relates to their own research.
Back
to the Writing up Research homepage
The
Basics of Good Writing
How to
reference
References
(for works cited in Writing up
Research)
Useful
writing links
