Literature review
A literature review is a critical overview of the published research on a topic. It does not list papers one by one. It groups them, compares what they found and shows what is still unknown, so the reader sees where your own question fits. It can be a chapter in a thesis or a stand-alone paper.
In more detail
The difference between a summary and a review is synthesis. A summary says what each paper found. A review says what the papers say together: where they agree, where they conflict, which methods they share and what none of them has tested. A paragraph that opens with an author's name usually gives the problem away, because a good paragraph opens with an idea and cites several authors for it.
A review has three jobs: show that you know the field, justify your question by pointing at a gap, and give the reader a map of the debate. Length depends on the setting: a few pages for a course paper, a full chapter for a thesis, a whole article for a stand-alone or systematic review.
Keep a record of every search. Write down the databases, the exact search terms, the dates and the filters you used. It makes the work repeatable, stops you running the same search twice, and systematic reviews require it.
Four ways to organize a literature review
| Approach | Groups sources by | Use it when |
|---|---|---|
| Thematic | Topics or concepts | It is the default for most reviews |
| Chronological | When the work appeared | The field changed over time |
| Methodological | The methods used | Studies disagree because of how they were run |
| Theoretical | Competing theories | The debate is about explanation |
Example
Dev is writing a 12-page paper on sleep and exam performance. He reads 22 papers and puts them in a table. Nine link sleep after studying to better recall, seven find that all-nighters hurt exam scores, and six study other outcomes. None follows students across a whole semester. His review has three sections, one per theme, and the last paragraph names that missing semester-long study as the gap his own question addresses.
How to use it
- 1
Define the scope. Turn your topic into one question and set limits: years, field, languages and types of study. A review of everything about memory is not a review.
- 2
Search. Use Google Scholar and your library's databases with synonyms and combined terms. Then follow citations backward through a good paper's reference list and forward through the papers that cite it. Log every search.
- 3
Read and screen. Read the abstract first and drop papers that miss your scope. For the rest, note the question, method, sample, main finding and limitation in one row of a table.
- 4
Synthesize. Sort the rows by theme and ask what the group shows: agreement, conflict, patterns by method and gaps. Write one sentence per theme that states the point before you cite anyone.
- 5
Structure and write. Open with the scope and the question, give each theme its own section, and close by naming the gap and linking it to your own study. Cite as you write and check each claim against the source page.
How StudyPDF does this
StudyPDF helps with the reading, not the writing. Upload the papers into one course, scanned ones included, and get a summary of each with inline citations that link to the page. Then ask questions across the whole set, such as which papers used interviews, and every answer cites the page it came from, so you can check it before it goes into your text. The thinking stays yours: you pick the themes and you write the review.
See also
Common questions
Is a literature review the same as a summary?
No. A summary reports what each source says. A literature review compares sources, groups them by theme and shows what is missing, so it answers a question that no single source answers on its own.
How many sources does a literature review need?
There is no fixed number. A course paper often cites 10 to 20 sources and a thesis chapter dozens. A useful sign to stop searching is that new searches mostly return papers you have already found.
Put it to work on your own course
Upload your lectures and ask Bo. Cited answers, plus flashcards, exams, and more built from your material.