Description
Here are some ideas for your post to get you started:
Discuss your personal preference of organizing your sources during a literature review. Have you tried using a literature map? Does using a literature map seem useful or helpful given your own approach to organizing your sources?
After completing the readings for this week, share which reading most interested you or you felt was most immediately relevant to your own professional or academic career.
student 1
When I first began learning about literature reviews, they were slightly intimidating. I was always concerned how I would narrow down all the articles found that relate to the specific topic I was researching. It definitely does help to have a title first, as this will aid in knowing what key words to plug into the database(Creswell, J.W., & Creswell, J. D., 2022). As someone who likes to see things before them, written down, learning about the literary map has opened my eyes quite a bit. Being able to list everything in front of me, then decipher through it all to come up with a topic sounds much easier than struggling with various database articles. Many topics that we look to research are “umbrella categories,” and using a literary map will help break everything down into subcategories(Creswell, J.W., & Creswell, J. D., 2022).
In regard to the articles assigned for this week, the article by Xiao et al, I found more intriguing to read. I found the article provide more context and detail on how to conduct a literature review. It was a well-organized article which broke down into sections such as methodology, typology, explaining the process, and tips on how to improve the reviews(Xiao, Y., et al. 2019). The information gained from this article will absolutely assist in the literature reviews I will have to write while obtaining my MS, as well as in my dissertation for my doctorate.
Reference
Creswell, J. W., & Creswell, J. D. (2022). Research Design (6th ed.). SAGE Publications, Inc. (US). https://capella.vitalsource.com/books/9781071817964
Xiao, Y., & Watson, M. (2019). Guidance on conducting a systematic literature review. Journal of planning education and research, 39(1), 93-112. https://doi-org.library.capella.edu/10.1177/0739456X17723971
student 2
A literature map is a handy tool for researchers to visualize connections between various sources. It helps in the organization and analysis of sources, revealing gaps in knowledge and new research opportunities. This tool is particularly helpful for complex research projects or when tracking a large number of sources.
With a literature map, researchers can effortlessly identify the relationships between different sources, emerging themes, and critical ideas. It also helps in identifying areas that require further research, as well as keeping track of project progress.
In conclusion, utilizing a literature map is an effective way to organize sources and gain a better understanding of research topics.
student 3
in my readings this week, I discovered that I would probably be more interested in a mixed methods structure study approach. I would want to use a combination of quantitative and qualitative research methods while doing a literature review because I think this could help extract more information and data from a study than just using one or the other.
Although Cooper (2010) discusses four types of literature reviews: (a) integrate what others have done and said, (b) criticize previous scholarly works, © build bridges between related topics, and (d) identify the central issues in a field, there are questions to be asked first.
According to Creswell & Creswell (2023), the most important question is whether the topic adds to the pool of research knowledge in the literature available on the topic.
I have never specifically used a literature map in the past to organize my research. I have always started by arriving at a narrow topic of choice and then creating keywords and doing research via online databases. Although this is very similar to the steps outlined in the article, “Guidance on Conducting a Systematic Literature Review”. According to Xiao and Watson (2017), “There are a few lessons to be learned while conducting a literature review: first, start with a research question, second, choose a review type suitable for the review purpose, third, plan before you leap, fourth, be comprehensive int he literature search and be aware of the quality of literature, fifth, be cautious, flexible, and open-minded, sixth, document decision made in the review process, seventh, teamwork is encouraged in the review process, and finally, offer a remark on the technology and software available for facilitating systematic review.”
While I believe that I have a good grasp of the organization of a literature review, I do believe that the map is the way to go. It organizes your organization. Does that make sense? I love everything about it.
I loved the reading, “Guidance on Conducting a Systematic Literature Review”. Although I have a base knowledge for organizing my research, this added some perspective.
Cooper, J. O., Heron, T. E. & Howard, W. L. (2007). Applied behavior analysis. Pearson/Merrill-Prentice Hall.
Creswell, J. W., & Creswell, J. D. (2023). Research design: Qualitative, quantitative, and mixed methods approaches (6th ed.). Sage.
Xiao, Y., & Watson, M. (2017). Guidance on conducting a systematic literature review. Journal of Planning Education and Research, 39(1), 93–112.
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650133
research-article2016
URO0010.1177/2051415816650133Journal of Clinical UrologyWinchester and Salji
Clinical Research Toolkit
Journal of Clinical Urology
2016, Vol. 9(5) 308–312
© British Association of
Urological Surgeons 2016
Reprints and permissions:
sagepub.co.uk/journalsPermissions.nav
DOI: 10.1177/2051415816650133
uro.sagepub.com
Writing a literature review
Catherine L Winchester1 and Mark Salji1,2
Abstract
Formal literature reviews are a critical appraisal of a subject and are not only an academic requirement but essential
when planning a research project and for placing research findings into context. Understanding the landscape in which
you are working will enable you to make a valuable contribution to your field. Writing a literature review requires a
range of skills to gather, sort, evaluate and summarise peer-reviewed published data into a relevant and informative
unbiased narrative. Digital access to research papers, academic texts, review articles, reference databases and public data
sets are all sources of information that are available to enrich your review.
Keywords
Critical appraisal, published literature, evidence, unbiased synopsis, evaluation, review, summary
Date received: 4 February 2016; revised: 1 April 2016; accepted: 19 April 2016
Introduction
A formal literature review is an evidence-based, in-depth
analysis of a subject. There are many reasons for writing
one and these will influence the length and style of your
review, but in essence a literature review is a critical
appraisal of the current collective knowledge on a subject.
Rather than just being an exhaustive list of all that has been
published, a literature review should be an informative,
personal but unbiased synopsis of the information, providing a balanced view that includes conflicting findings and
inconsistencies, as well as established and current thinking. A literature review differs from a systematic review,
which addresses a specific clinical question by combining
the results of multiple clinical trials (an article on this topic
will follow as part of this series of publications). A formal
literature review is also an extension of the information
gathering you might do to get a personal insight to the
background of a topic and requires more than a quick scan
of the literature and a few summary bullet points.
Conducting a literature review is essential for developing a research idea, to consolidate what is already known
about a subject and to enable you to identify any knowledge gaps and how your research could contribute to further understanding. This will help you develop hypotheses
and to frame your research question; see the article by
Anastasiadis et al. for further reading.1 Once you’ve carried out a piece of research, a literature review is also crucial for evaluating your data and determining their
relevance and clinical utility. Research data without context can be meaningless. A literature review will enable
you to identify other research that supports or corroborates
your findings as well as results that differ, enabling you to
position your research in the field. The dissemination of
your research findings, whether by publication in a peerreviewed paper or by oral presentation, will use the information gathered for a literature review, thus providing
reference points for your new data and helping to identify
and deliver the potential impact of your research.
This is also important for obtaining funding to support
research. Not only do grant funders require background
1Cancer Research UK Beatson Institute, Glasgow, UK
2Institute of Cancer Sciences, University of Glasgow, UK
Corresponding author:
Catherine L Winchester, Cancer Research UK Beatson Institute,
Garscube Estate, Bearsden, Glasgow, G61 1BD, UK.
Email: [email protected]
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Winchester and Salji
information on your research to illustrate its scientific relevance, but identifying beneficiaries and the potential
impact of your results in addressing an area of unmet need
are often key areas in grant applications.
You may be required to write a literature review as
coursework and this is certainly the case if you undertake
a postgraduate research degree (e.g. MSc, MD or PhD).
Not only will you write a literature review during the initial phase or first year of study, but it will form a major part
of your dissertation or thesis. As well as being the introduction to your own work, demonstrating your knowledge
and understanding of your field, it will also be used in the
discussion of your results, thereby putting your research
findings into context with published data.
Your motivation for conducting a literature review
might be personal interest in a subject of relevance to
your clinical speciality. In this case you are likely to
know the background to your field and be more interested in recent findings and new advances that could
impact on patient treatment and care. A less formal
approach may be adopted for scanning the literature in
such a case or when collation of information is required
for a colloquial setting such as a journal club or consolidating basic background information.
Finally, you may have been commissioned to write a
literature review by a journal editor or choose to submit
your own formal literature review for publication.
How to conduct a literature review
Conducting a literature review requires you to gather
information on a subject or evidence to support a hypothesis in order to contextualise research data. These days,
knowledge is at our fingertips and we can readily access
online information via sophisticated search engines, such
as Google,2 without even having to enter a library.
The first step is to identify broad keywords relevant to
your subject. These require careful consideration, as they
are responsible for directing your literature search and
affect the material you will acquire to read. They have the
additional function of being used by search engines to
construct and index their archived references, enabling
you to access a vast catalogue of information online. Later
on these keywords can be expanded to refine the search
into specific subheadings and enable you to structure your
review. A convenient way to start your literature search
can be to use published review articles or academic text
books to learn the background to a subject. This might
help you to compile your list of keywords, identify areas
that you want to explore further and to see which articles
other people have read. However, it is important to
remember that reviews are written from someone else’s
viewpoint and should not be the foundation of your literature review.
It is essential to read published peer-reviewed original
research articles to formulate your literature review. Try to
strike a balance between old established papers and current
ones, which refute as well as support a particular idea or
research finding. Generate a reading list by searching
online citation databases such as PubMed®,3 which incorporates MEDLINE®,4 or Europe PubMed Central (PMC).5
The text-mining capabilities of these sites allow you to
identify peer-reviewed original research articles, review
papers, book chapters and, in the case of Europe PMC,
patents and NHS guidelines that encompass your keywords. As well as generating a list of articles, both
PubMed® and Europe PMC provide free access to the
associated abstracts. This is really useful as one can
quickly determine whether the paper is of interest or relevant to your literature review. However, it is essential to
read the entire article so that you can assess the evidence
and summarise the findings in your own words. Many articles are now published with open access and so can be
obtained directly from a journal’s website for free. In addition, Europe PMC has over 3.5 million full text articles
available directly. Use your medical school or university
library’s subscription to journals to obtain older articles
that are not available digitally or those that are not published under open access. In some cases these libraries
may also be able to obtain papers from other libraries, such
as the British Library.
Another source of information is searchable online
reference databases like MalaCards,6 the human disease
database that integrates a wealth of clinical information
with data on clinical trials, molecular bases of disease
and experimental resources from other reference databases and published research. Online pathway tools, such
as Reactome,7 can also be used to access collective
knowledge of molecular interactions with disease.
Mining large public data sets, both clinical and molecular, has in recent years become far more achievable and
can provide information to strengthen your review.
Querying such large community resources in a relevant
manner for your review is often possible using online
tools, such as use of the c-BioPortal to interrogate The
Cancer Genome Atlas.8,9
Reducing bias in a literature review
It is important to be mindful of introducing bias, as preconceived ideas about your subject area, whether intentional
or not, can affect all stages of writing a literature review,
from identifying literature sources, selecting articles to
include and your evaluation of the evidence. Using a protocol can be a useful approach to reduce bias. Begin by
determining the objectives and scope of your review, as
this will help to set boundaries and focus your keyword
selection. This will also aid the structuring of your review
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Journal of Clinical Urology 9(5)
Table 1. Key stages of writing a literature review.
Stages
Example
Select review topic/title
Biomarkers for prostate cancer
Identify keywords and
search terms
biomarkers for prostate cancer, prostate cancer screening and disease monitoring, prostate
specific antigen (PSA), prostate cancer antigen 3 (PCA3), prostate health index (PHI), genetic
markers for prostate cancer (TMPRSS2-ERG), new protein biomarkers for prostate cancer
(KLK2), tissue (urine/blood)
Identify information sources
Online search engines: Google2
Online citation databases: Europe PubMed Central5
Online reference databases: MalaCards6
Clinical resources: NICE,13 Cochrane14
Charity websites: Prostate Cancer UK15
Generate reading list and
collect articles
•• Start with broad search term e.g. ‘biomarkers for prostate cancer’
•• Use online resources:
Google results: journal articles, pharmaceutical and biotechnology company websites
Europe PMC results: 23,220 articles, 7253 reviews, 180 patents, 97 documents
MalaCards results: MCID: PRS040 webpage (68 reference sources)
NICE results: Diagnostic guidance DG17
Cochrane results: 6,593 articles
Prostate Cancer UK results: 26 articles
•• Scan article titles and abstracts to generate an unbiased reading list
•• Collect articles to read; open access, journal subscriptions, inter-library loans, freely available
Make notes in your own
words
•• Group and collate information relating to keywords and search terms:
e.g. utility of biomarkers, established biomarkers, new biomarkers, biological samples,
development of new biomarkers
•• Evaluate data in peer reviewed research articles
•• Compare and contrast similarities and differences
•• Keep track of information sources
Write literature review
•• Summarise findings
e.g. PCA3 in early detection of prostate cancer: sensitivity range 46–82% and specificity range
52–92%.16
•• Expand into full review using keywords and search terms to structure the text into sections
•• Generate a citation list
into sections that address specific areas or research questions. Next identify multiple sources for your reference
material to obtain a more comprehensive collection of
information. Selection of articles to include is where bias
in literature reviews is often most apparent. Avoid ‘cherry
picking’ articles that only support your hypothesis, agree
with your opinion on a subject or corroborate your research
findings. Including inclusion or exclusion criteria in your
protocol may circumvent this and result in a more consistent and unbiased approach to material selection. Evaluation
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Winchester and Salji
of the quality of studies and assessment of factors, such as
study design, data collection, data analysis and interpretation and the conclusions drawn by article authors, are also
essential. Finally, bias can be introduced by your own
interpretation of published research data.
••
••
How to write a literature review
When writing a literature review it is important to start
with a brief introduction, followed by the text broken up
into subsections and conclude with a summary to bring
everything together. A summary table including title,
author, publication date and key findings is a useful feature
to present in your review (see Table 1 for an example).
This will make your article informative and manageable to
read. You should group similar findings and comment on
differences in results or study outcomes. This may be due
to differences in subjects, experimental materials, methodology or how the data were analysed. Remember to consider negative findings by consulting sources such as the
Journal of Negative Results in Biomedicine.10
A literature review is not just about reporting published
facts; it requires careful consideration of the published literature to construct an unbiased narrative supported by
published evidence. Whilst summarising published findings, it is important for you to add perspective by commenting on the quality of the evidence presented. Whilst
not as formal as a systematic review, interpretation of the
data and assessment of the data quality are essential to give
your literature review gravitas and to reduce bias. For clinical research this can be the evidence level, using guidelines such as those developed by the Centre for Evidence
Based Medicine (CEBM).11 The CEBM level enables
individuals to assess the strength of evidence relating to
clinical questions by following a series of steps. For laboratory-based research, consideration of experimental protocols, data collection, data processing and statistical
analysis can give an indication of data quality, reliability
and reproducibility.
Be careful not to plagiarise other authors’ text by
acknowledging work that is not your own, ensuring your
opinions can be clearly recognised by the reader.12 Writing
notes as you read the reference articles, keeping track of
these references, citing correctly and writing your review
from these notes can help with this. Understanding your
target audience is useful for pitching the depth and content
of your literature review. Ultimately your literature review
should be a critical appraisal of a subject, with your perspective on the merit of the literature you have read.
Take home messages
•• A literature review should set the scene, demonstrate current knowledge, identify gaps in the field
••
••
••
and, if relevant, demonstrate where your research
fits.
It should be a personal critical appraisal of the current knowledge in a subject area.
It should be evidence-based, using a variety of
peer-reviewed original research articles, reporting
facts, commenting on similarities or discrepancies
and highlighting knowledge gaps or areas of unmet
need.
Structure your review with an introduction, subsections and a summary table.
Summarise information in your own words and give
appropriate credit to other authors’ work.
A systematic approach to writing a literature review
should be used to reduce bias.
Conflicting interests
The authors declare that there are no conflicts of interest.
Funding
This work was supported by Cancer Research UK (grant number
A17196) and the Medical Research Council (grant number
70128).
Ethical approval
Not applicable.
Informed consent
Not applicable.
Guarantor
CW.
Contributorship
CW produced the first draft of the manuscript and MS made
additions and edits to it. Both authors reviewed and approved the
final version of the manuscript.
Acknowledgements
This article was commissioned by the BAUS Section of Academic
Urology.
References
1. Anastasiadis E, Rajan P and Winchester CL. Framing a
research question: the first and most vital step in planning
research. J Clin Urol 2015; 8: 409–411.
2. Google. www.google.co.uk (accessed 9 May 2016).
3. National Center for Biotechnology Information. PubMed®,
www.ncbi.nlm.nih.gov/pubmed (accessed 9 May 2016).
4. US National Library of Medicine. MEDLINE® fact sheet,
www.nlm.nih.gov/pubs/factsheets/medline.html (accessed
9 May 2016).
312
5. Europe PubMed Central. https://europepmc.org (accessed 9
May 2016).
6. MalaCards. www.malacards.org (accessed 9 May 2016).
7. Reactome. www.reactome.org (accessed 9 May 2016).
8. c-BioPortal. www.cbioportal.org (accessed 9 May 2016).
9. National Institutes of Health. The Cancer Genome Atlas,
http://cancergenome.nih.gov (accessed 9 May 2016).
10. BioMed Central. Journal of Negative Results in Biomedicine, http://jnrbm.biomedcentral.com (accessed 9
May 2016).
11. Centre for Evidence Based Medicine. OCEBM levels of evidence, www.cebm.net/ocebm-levels-of-evidence (accessed
9 May 2016).
Journal of Clinical Urology 9(5)
12. University of Glasgow. What is plagiarism?, www.gla.
ac.uk/services/sls/plagiarism/whatisplagiarism/ (accessed 9
May 2016).
13. National Institute for Health and Care Excellence (NICE).
Diagnosing prostate cancer – PROGENSA PCA3 assay
and Prostate Health Index, www.nice.org.uk/guidance/
indevelopment/gid-dt20 (accessed 9 May 2016).
14. Cochrane. www.cochrane.org (accessed 9 May 2016).
15. Prostate Cancer UK. http://prostatecanceruk.org (accessed 9
May 2016).
16. Luo Y, Gou X, Huang P, et al. Prostate cancer antigen 3 test
for prostate biopsy decision: a systematic review and meta
analysis. Chin Med J 2014; 127: 1768–1774.
723971
research-article2017
JPEXXX10.1177/0739456X17723971Journal of Planning Education and ResearchXiao and Watson
Planning Research
Guidance on Conducting a Systematic
Literature Review
Journal of Planning Education and Research
2019, Vol. 39(1) 93–112
© The Author(s) 2017
Article reuse guidelines:
sagepub.com/journals-permissions
https://doi.org/10.1177/0739456X17723971
DOI: 10.1177/0739456X17723971
journals.sagepub.com/home/jpe
Yu Xiao1 and Maria Watson1
Abstract
Literature reviews establish the foundation of academic inquires. However, in the planning field, we lack rigorous systematic
reviews. In this article, through a systematic search on the methodology of literature review, we categorize a typology of
literature reviews, discuss steps in conducting a systematic literature review, and provide suggestions on how to enhance
rigor in literature reviews in planning education and research.
Keywords
literature review, methodology, synthesis, typology
Introduction
Research Methodology for This Study
Literature review is an essential feature of academic research.
Fundamentally, knowledge advancement must be built on
prior existing work. To push the knowledge frontier, we must
know where the frontier is. By reviewing relevant literature,
we understand the breadth and depth of the existing body of
work and identify gaps to explore. By summarizing, analyzing, and synthesizing a group of related literature, we can test
a specific hypothesis and/or develop new theories. We can
also evaluate the validity and quality of existing work against
a criterion to reveal weaknesses, inconsistencies, and contradictions (Paré et al. 2015).
As scientific inquiries, literature reviews should be
valid, reliable, and repeatable. In the planning field, we
lack rigorous systematic reviews, partly because we rarely
discuss the methodology for literature reviews and do not
provide sufficient guidance on how to conduct effective
reviews.
The objective of this article is to provide guidance on
how to conduct systematic literature review. By surveying
publications on the methodology of literature review, we
summarize the typology of literature review, describe the
procedures for conducting the review, and provide tips to
planning scholars.
This article is organized as follows: The next section
presents the methodology adopted by this research, followed by a section that discusses the typology of literature
reviews and provides empirical examples; the subsequent
section summarizes the process of literature review; and
the last section concludes the paper with suggestions on
how to improve the quality and rigor of literature reviews
in planning.
Literature Search and Evaluation
Inclusion criterion. We only included studies that provide
guidance on the methodology of conducting a literature
review. Literature reviews on a specific topic were excluded
from this study. We included studies from all disciplines,
ranging from medical and health science to information systems, education, biology, and computer science. We only
included studies written in English.
Literature identification. We started the literature search by
using the keywords “how to conduct literature review”,
“review methodology,” “literature review,” “research synthesis,” and “synthesis.” For each manuscript, preliminary
relevance was determined by title. From the title, if the content seemed to discuss the methodology of the literature
review process, we obtained its full reference, including
author, year, title, and abstract, for further evaluation.
We searched Google Scholar, Web of Science, and
EBSCOhost, three frequently used databases by researchers
across various disciplines. Because technological advancement changes methods for archiving and retrieving
Initial submission, November 2016; revised submission, February 2017;
final acceptance, June 2017
1
Texas A&M University, College Station, TX, USA
Corresponding Author:
Yu Xiao, Department of Landscape Architecture and Urban Planning,
Texas A&M University, 3137 TAMU, College Station, TX 77843-3137,
USA.
Email: [email protected]
94
information, we limit the publication date to 1996 and 2016
(articles published in the past twenty years), so that we can
build our review on the recent literature considering information retrieval and synthesis in the digital age. We first
searched Google Scholar using broad keywords “how to conduct literature review” and “review methodology.” After
reviewing the first twenty pages of search results, we found
a total of twenty-eight potentially relevant articles. Then, we
refined our keywords. A search on Web of Science using
keywords “review methodology,” “literature review,” and
“synthesis” yielded a total of 882 studies. After initial screening of the titles, a total of forty-seven studies were identified.
A search on EBSCOhost using keywords “review methodology,” “literature review,” and “research synthesis” returned
653 records of peer-reviewed articles. After initial title
screening, we found twenty-two records related to the methodology of literature review. Altogether, three sources combined, we identified ninety-seven potential studies, including
five duplicates that we later excluded.
Screening for inclusion. We read the abstracts of the ninetytwo studies to further decide their relevance to the research
topic—the methodology of literature review. Two researchers performed parallel independent assessments of the manuscripts. Discrepancies between the reviewers’ findings were
discussed and resolved. A total of sixty-four studies were
deemed relevant and we obtained the full-text article for
quality assessment.
Quality and eligibility assessment. We skimmed through the
full-text articles to further evaluate the quality and eligibility
of the studies. We deemed journal articles and books published by reputable publishers as high-quality research, and
therefore, included them in the review. Most of the technical
reports and on-line presentations are excluded from the
review because of the lack of peer-review process. We only
included very few high-quality reports with well-cited
references.
The quality and eligibility assessment task was also performed by two researchers in parallel and independently.
Any discrepancies in their findings were discussed and
resolved. After careful review, a total of eighteen studies
were excluded: four were excluded because they lacked
guidance on review methodology; four were excluded
because the methodology was irrelevant to urban planning
(e.g., reviews of clinical trials); one was excluded because it
was not written in English; six studies were excluded because
they reviewed a specific topic. We could not find the full text
for three of the studies. Overall, forty-six studies from the
initial search were included in the next stage of full-text
analysis.
Iterations. We identified an additional seventeen studies
through backward and forward search. We also utilized the
forward and backward search to identify literature review
Journal of Planning Education and Research 39(1)
methods. Once the article establishing the review methodology was found, we identified best-practice examples by
searching articles that had referenced the methodology paper.
Examples were chosen based on their adherence to the
method, after which preference was given to planning or
planning-related articles. Overall, thirty-seven methods and
examples were also included in this review.
Altogether, we included a total of ninety-nine studies in
this research.
Data Extraction and Analysis
From each study, we extracted information on the following
two subtopics: (1) the definition, typology, and purpose of
literature review and (2) the literature review process. The
literature review process is further broken down into subtopics on formulating the research problem, developing and
validating the review protocol, searching the literature,
screening for inclusion, assessing quality, extracting data,
analyzing and synthesizing data, and reporting the findings.
All data extraction and coding was performed using NVivo
software.
At the beginning, two researchers individually extracted
information from articles for cross-checking. After reviewing a few articles together, the two researchers reached consensus on what to extract from the articles. Then, the
researchers split up the work. The two researchers maintained frequent communication during the data extraction
process. Articles that were hard to decide were discussed
between the researchers.
Typology of Literature Reviews
Broadly speaking, literature reviews can take two forms: (1)
a review that serves as background for an empirical study
and (2) a stand-alone piece (Templier and Paré 2015).
Background reviews are commonly used as justification for
decisions made in research design, provide theoretical context, or identify a gap in the literature the study intends to fill
(Templier and Paré 2015; Levy and Ellis 2006). In contrast,
stand-alone reviews attempt to make sense of a body of
existing literature through the aggregation, interpretation,
explanation, or integration of existing research (Rousseau,
Manning, and Denyer 2008). Ideally, a systematic review
should be conducted before empirical research, and a subset
of the literature from the systematic review that is closely
related to the empirical work can be used as background
review. In that sense, good stand-alone reviews could help
improve the quality of background reviews. For the purpose
of this article, when we talk about literature reviews, we are
referring to the stand-alone literature reviews.
The stand-alone literature review can be categorized by
the purpose for the review, which needs to be determined
before any work is done. Building from Paré et al. (2015) and
Templier and Paré (2015), we group literature reviews into
Xiao and Watson
four categories based on the review’s purpose: describe, test,
extend, and critique. This section provides a brief description
of each review purpose and the related literature review
types. Review methodology differentiates the literature
review types from each other—hence, we use “review type”
and “review methodology” interchangeably in this article.
Table 1 can be used as a decision tree to find the most suitable review type/methodology. Based on the purpose of the
review (column 1 in Table 1) and the type of literature (column 2), researchers can narrow down to possible review type
(column 3). We listed the articles that established the specific
type of review in column 4 of Table 1 and provided an example literature review in column 5.
It should be noted that some of the review types have been
established and practiced in the medical sciences, so there
are very few examples of literature reviews utilizing these
methods in the field of urban planning and the social sciences, in general. Because the goal of this article is to make
urban planners aware of these established methods to help
improve review quality and expand planners’ literature
review toolkit, we included those rarely used but potentially
useful methods in this paper.
Describe
The first category of review, whose aim is descriptive, is the
most common and easily recognizable review. A descriptive
review examines the state of the literature as it pertains to a
specific research question, topical area, or concept. What
distinguishes this category of review from other review categories is that descriptive reviews do not aim to expand upon
the literature, but rather provide an account of the state of the
literature at the time of the review.
Descriptive reviews probably have the most variation in
how data are extracted, analyzed, and synthesized. Types of
descriptive reviews include the narrative review (Green,
Johnson, and Adams 2001), textual narrative synthesis
(Popay et al. 2006; Lucas et al. 2007), metasummary
(Sandelowski, Barroso, and Voils 2007), meta-narrative
(Greenhalgh et al. 2005), and scoping review (Arksey and
O’Malley 2005).
Narrative review. The narrative review is probably the most
common type of descriptive review in planning, being the
least rigorous and “costly” in terms of time and resources.
Kastner et al. (2012) describes these reviews as “less concerned with assessing evidence quality and more focused on
gathering relevant information that provides both context
and substance to the authors’ overall argument” (4). Often,
the use of narrative review can be biased by the reviewer’s
experience, prior beliefs, and overall subjectivity (Noordzij
et al. 2011, c311). The data extraction process, therefore, is
informal (not standardized or systematic) and the synthesis
of these data is generally a narrative juxtaposition of evidence. These types of reviews are common in the planning
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literature. A well-cited example would be Gordon and Richardson (1997), who use narrative review to explore topics
related to the issue of compact development. The review is a
persuasive presentation of literature to support their overall
conclusions on the desirability of compact development as a
planning goal.
Textual narrative synthesis. Textual narrative synthesis, outlined and exemplified by Popay et al. (2006) and Lucas et al.
(2007), is characterized by having a standard data extraction
format by which various study characteristics (quality, findings, context, etc.) can be taken from each piece of literature. This makes it slightly more rigorous than the standard
narrative review. Textual narrative synthesis often requires
studies to be organized into more homogenous subgroups.
The synthesis will then compare similarities and differences
across studies based on the data that was extracted (Lucas
et al. 2007). Because of the standardized coding format, the
review may include a quantitative count of studies that has
each characteristic (e.g., nine of sixteen studies were at the
neighborhood level) and a commentary on the strength of
evidence available on the research question (Lucas et al.
2007). For example, Rigolon (2016) uses this method to
examine equitable access to parks. The author establishes
the coding format in table 2 of the article, and presents a
quantitative count of articles as evidence for sub-topics of
park access, such as acreage per person or park quality (e.g.,
the author shows that seven articles present evidence for
low-socioeconomic status groups having more park acreage
versus twenty studies showing that high- and mid-socioeconomic status groups have more acreage) (Rigolon 2016,
164, 166).
Metasummary. A metasummary, outlined by Sandelowski,
Barroso, and Voils (2007), goes beyond the traditional narrative review and textual narrative synthesis by having both a
systematic approach to the literature review process and by
adding a quantitative element to the summarization of the
literature. A metasummary involves the extraction of findings and calculation of effect sizes and intensity effect sizes
based on these findings (more broadly known as
