What it is and why it is set
An annotated bibliography sits between a reference list and a literature review. Like a reference list, it is a series of correctly formatted citations; unlike one, each entry carries an annotation — a short paragraph assessing the source. Tutors set it for two reasons: it forces you to engage with each source rather than skim it, and it is excellent preparation for a literature review or research project, because by the end you have a digested map of your reading.
What each annotation contains
A full annotation usually does three jobs, in a paragraph of roughly 100–200 words:
- Summary — what the source argues, its main findings, and its scope.
- Evaluation — how credible, rigorous or useful it is; the author's authority; any bias or limitation.
- Reflection — how it fits your project: what it contributes, how it compares to other sources, and how you will use it.
Not every assignment wants all three — check your brief — but the reflection is what makes an annotation genuinely useful to you later.
Descriptive vs critical annotations
| Type | What it does |
|---|---|
| Descriptive (informative) | Summarises the source's content and scope without judging it. |
| Critical (evaluative) | Summarises and assesses the source's quality, relevance and limitations. |
Most university assignments want critical annotations — the evaluation is where you demonstrate judgement. A purely descriptive annotation reads like a blurb; a critical one reads like a scholar deciding whether a source can be trusted.
How to write an annotation
Read the source actively, noting its thesis, method, evidence and conclusion. Then write the citation in your required style, and follow it with a tight paragraph that moves from summary to evaluation to relevance. Keep it concise and in your own words — an annotation is not a place for long quotations. Write in complete sentences, in an academic tone, and stay consistent in length and depth across every entry so the bibliography reads as one considered document.
Smith, J. (2021). Remote learning and student outcomes. Routledge.
Smith argues that remote learning widens attainment gaps without structured support, drawing on a two-year study of 1,400 students. The large sample and longitudinal design make the findings credible, though the focus on one institution limits generalisability. The book is central to my project because it provides the empirical baseline against which I compare more recent pandemic-era data.
APA and MLA formatting
The citation above each annotation follows the same rules as a normal reference, so it should match your reference-list style exactly. In APA, entries are alphabetical with a hanging indent, and the annotation begins on a new line, indented as a block. In MLA, the works-cited entry is followed by the annotation, also indented. The annotations themselves are formatted as ordinary prose. See our APA and MLA guides for the citation details, and always order entries alphabetically by the first author's surname unless told otherwise.
Common mistakes to avoid
- Pure summary with no evaluation, when the brief wants critical annotations.
- Inconsistent length or depth across entries.
- Citations that do not match your required style or are not in alphabetical order.
- Quoting heavily instead of summarising in your own words.
- Skipping the "how I will use this" reflection that makes the annotation useful later.
Frequently asked questions
How long should each annotation be?
Usually one paragraph of about 100 to 200 words, though it depends on the assignment. Whatever length you choose, keep it consistent across every entry so the bibliography reads as one document.
What is the difference between a descriptive and a critical annotation?
A descriptive annotation only summarises the source’s content, while a critical annotation also evaluates its credibility, relevance and limitations. Most university assignments require critical annotations.
How is an annotated bibliography different from a literature review?
An annotated bibliography assesses each source separately, entry by entry, while a literature review synthesises sources together around themes and arguments. The bibliography is often a stepping stone toward writing the review.