What Is a Literature Review?
One sentence in the supplied teaching source carries the whole week. Get that sentence right and everything downstream — searching, judging sources, structuring, writing — becomes technique in service of a single purpose rather than a list of unrelated chores.
The definition, and the four phrases that do the work
The supplied teaching source opens the topic with a single-sentence definition and then spends the rest of the week unpacking it. It is worth reading slowly, because four separate constraints are packed into it and each one rules out a different way of getting the review wrong.
The four constraints inside the definition
- Critical and evaluative
- You are judging, not reporting. Every work you include has to be weighed — against the other works, and against your topic. A neutral account of what each author said satisfies neither adjective.
- Summary
- Compression is required. The review is shorter than what it reviews, which means selection and omission are part of the method rather than a failure of thoroughness.
- Of the themes, issues and arguments
- The unit of organisation is the theme, the issue or the argument — not the article. This single phrase is what separates a review from a list, and the source restates it three separate times.
- Of a specific clearly defined research topic
- The boundary comes first. Without a defined topic you have no basis for deciding what is relevant, and the review becomes unbounded reading.
The fifth phrase — "published (and unpublished)" — is the one the source states and then leaves alone. It grants you the right to use unpublished work, but it never says what qualifies, how you would judge it, or how it should be cited. Read it as permission rather than as guidance.
The four stated aims
The source lists four aims. They are worth treating as a specification for the finished chapter rather than as a description of the activity, because each one leaves a visible trace in the document and each one is visibly absent when it has been skipped.
THE FOUR AIMS AND WHAT EACH ONE LEAVES BEHIND
| Aim, as stated | What it produces in your document | How you can tell it is missing |
|---|---|---|
| Define the particular field of research | An opening that states what territory you are working in, and what sits outside it | The reader cannot tell where the boundary is, so cannot tell whether an omission is a decision or an oversight |
| Introduce and explain findings that support the research questions | A traceable line from the published findings to the questions you intend to ask | The research questions arrive with no visible ancestry — they could have been written before any reading was done |
| Summarise the findings of the relevant readings | Compressed, evaluated accounts of what is known, grouped by theme | Article-by-article description, or a bibliography with commentary attached |
| Identify gaps that point to the significance of the research to follow | An explicit statement of the shortfall and of why closing it matters | The review ends by summarising the field and then simply asserts that the study is worth doing |
The four aims are the source's own. The second and third columns are a working reading of them, offered to make each aim checkable in a draft.
The fourth aim carries the most weight and is the one most often left implicit. The source is explicit that the review "refers to the 'gap' in literature and the significance of the research in addressing whatever the shortfall may be" — the gap is not a by-product of the review, it is one of the four things the review exists to produce. That work has its own page at identifying the gap in the literature.
The five things it gives an overview of
Alongside the aims, the source states what the review gives an overview of — it calls this "the field of inquiry". These five items are a useful audit of coverage: if you cannot answer all five about your topic, your search is not finished.
An overview of the field of inquiry
What has already been said on the topic
The accumulated content of the field. This is the item most people assume is the whole job, and it is one of five.
Who the key writers are
The field has a shape, and some contributors define it. Knowing who they are tells you whose absence from your reference list a reader would notice.
What the prevailing theories and hypotheses are
The explanatory frames currently in use. Your own conceptual framing either adopts one of these, adapts one, or has to argue for departing from all of them.
What questions are being asked
The live questions, as distinct from the settled findings. This is the item that most directly feeds your own research question.
What methodologies and methods are appropriate and useful
The review is where your methodology chapter gets its options and its precedents. What comparable studies did, and what they found workable, is evidence you can cite.
Item five is easy to skip and expensive to skip. If you read only for content, you finish the review knowing what the field believes and nothing about how it found out — and you then have to justify your design from first principles instead of from precedent. The catalogue of options is set out separately on choosing a research methodology.
What makes a review critical rather than descriptive
The source treats "a critical literature review" as a distinct thing and describes it in one dense passage. Three obligations are contained in it.
A critical literature review shows how prevailing ideas fit into your own research topic, and how your topic or theory agrees or differs from them. It is a structured presentation that gradually narrows down from the accepted findings to the unresolved issues ending with a statement of the research questions and their significance to the knowledge base.
- Fit. Show how the prevailing ideas relate to your topic. Not what the ideas are — how they bear on the thing you are studying.
- Position. State where your topic or theory agrees with them and where it differs. This is an argument you make, not a fact you report.
- Structure. Present it as a narrowing, from what is accepted through to what is unresolved, ending in your questions and their significance.
The narrowing, and how it looks on the page
The word "gradually" in the source's description matters. The review is not a wide survey followed by an abrupt statement of your question; it is a controlled reduction in scope, where each stage justifies the next.
- Accepted findings
- Agreements and differences
- Unresolved issues
- Your research questions
- Significance to the knowledge base
Consider a topic in an area the source itself names as a research theme — managing the transition from construction into operations. The following is an illustration of the shape of a narrowing, not a summary of any real body of work.
AN ILLUSTRATIVE NARROWING, FOUR LEVELS DEEP
| Level | What this stage of the review establishes | What it rules out of scope |
|---|---|---|
| The field | Handover between delivery and operations is treated in the literature as a recognised phase with its own failure modes | General delivery performance; anything that does not cross the delivery-to-operations boundary |
| Accepted findings | What the field agrees on about that phase — the widely repeated conclusions that no longer need arguing | Re-litigating settled ground; your review reports it and moves on |
| Disagreement | Where the works diverge — different theoretical assumptions, different definitions of a successful handover, contradictory conclusions | Treating divergence as noise. The divergence is the material |
| Unresolved issues | The specific question the disagreement leaves open, stated narrowly enough that a master's-scale study could address it | Everything the field has already resolved, and everything too large to study in your timeframe |
Illustrative only. No findings, agreements or disagreements are attributed to any real body of literature here — the table shows the shape of the movement, not its content.
Notice that the narrowing does the same job as topic scoping, one step later and with evidence attached. If the movement feels familiar it is because you have done it once already, from the other direction — see narrowing and scoping a research topic.
Two processes, and the pages that carry each
The source divides the whole exercise into two processes: the search for materials and resources, and writing your literature review. The division is more useful than it first looks, because the two halves fail differently and are done at different times of day, in different states of mind.
Process one — the search
- Search rules and strategies for finding relevant work
- Choosing and working a database systematically
- Judging the academic value and credibility of what you find
- Reading and interrogating an article before you commit to it
- Recording bibliographic details and notes as you go
Process two — the writing
- Summarising and paraphrasing without losing the author's emphasis
- Grouping works by theme and building the synthesis
- Structuring the review into introduction, body and conclusion
- Stating the gap and the significance that follows from it
- Referencing consistently in the required style
The two processes overlap in practice and the source does not claim otherwise — you will still be searching while you write, because writing exposes holes. Start with the search rules if you have a topic but no material, and with writing the literature review if you have a pile of reading and no chapter.
Checking a draft against the definition
Because the definition is a specification, it converts directly into a test. Apply it to the review you have, not to the one you intended to write.
Seven checks drawn from the source's own statements
- The topic is stated specifically enough that a reader could decide whether a given work belongs in the review
- Paragraphs are organised around themes, issues or arguments — not around one work each
- Similarities, differences, consistencies and inconsistencies between works are stated explicitly somewhere in the text
- The prevailing theories are named, and your topic's relationship to them is stated rather than implied
- The structure narrows: a reader can see the scope reducing from section to section
- The review ends in research questions, and those questions are visibly the product of what preceded them
- The significance of the research to the knowledge base is stated, and it is tied to a specific shortfall
What to carry forward
- The review is a critical and evaluative summary of themes, issues and arguments in a specific, clearly defined topic. Every phrase in that sentence is a constraint.
- Four aims: define the field, connect findings to your questions, summarise the readings, identify the gap that gives your study its significance.
- Five coverage checks: what has been said, who the key writers are, the prevailing theories, the live questions, and the methodologies in use.
- Critical means three things — show how prevailing ideas fit your topic, state where you agree and differ, and present it as a gradual narrowing that ends in your questions.
- The work splits into searching and writing. Both are covered in depth elsewhere in this stream; this page is the definition they all serve.
Frequently asked questions
How long should a literature review be?
The supplied teaching source sets no length and no minimum number of works. It says only that the kind of review you write, and the amount of detail, depend on the requirements of your studies. Treat the coverage checks — the five things the review gives an overview of — as a better completeness test than any word count.
What is the difference between a literature review and a critical literature review?
The source uses "critical" as an intensifier on the same activity rather than as a separate deliverable, but it describes the critical review specifically: it shows how prevailing ideas fit your topic, states how your topic agrees or differs from them, and narrows from accepted findings to unresolved issues and then to your questions. A review that does none of those three is descriptive, not critical.
Can I include unpublished work?
The definition explicitly names "published (and unpublished)" literature, so the source permits it. It gives no criteria for judging unpublished material, no guidance on citing it and no worked example, so you are on your own for the judgement — document your reasoning for including any unpublished source.
Do I write the review before or after deciding my research question?
Both, in that order and then again. The source describes the review as narrowing towards a statement of the research questions, which means the questions are an output of the review — but you need a specific, clearly defined topic before you can search at all. Expect the question to sharpen as the reading accumulates.
Where does the gap come from?
From the disagreements and silences you record while reading. The source names identifying gaps as one of the four aims and ties the gap directly to the significance of the research, but this section does not give a method for finding one. That is developed across the reading, writing and structuring guidance in this stream.
Is the review a chapter or an ongoing activity?
Both, and the source treats it as two processes — searching and writing — rather than as a single phase. The chapter is the visible output; the searching and reading run alongside your design work and usually continue after a first draft of the chapter exists.
References and source attribution
- The supplied teaching source: master's-level teaching material on reviewing the literature, supplied as a teaching document, accompanying slides and printed study notes. The definition, the four aims, the five overview items, the description of the critical review and the two-process division are all quoted or closely paraphrased from that material.
- O'Leary, Z. 2017, The Essential Guide to Doing Your Research Project, 3rd ed., Sage Publications, London — listed among the reference works cited by the supplied source.
- Bryman, A. 2016, Social Research Methods, 5th ed., Oxford University Press, Oxford — listed among the reference works cited by the supplied source.
- Naoum, S. G. 2013, Dissertation Research & Writing for Construction Students, 3rd ed., Routledge — set as reading in the supplied source's earlier material on topic development.
Suggested questions for Ask KEVOS
- What is the source's exact definition of a literature review?
- What are the four aims of a literature review?
- What makes a literature review critical rather than descriptive?
- How does a literature review narrow towards a research question?
- What does the supplied source not tell me about the scope of a literature review?