What Is an Annotated Bibliography?
Updated September 2026
An annotated bibliography is a reference list where each citation is followed by a short paragraph — the annotation — summarizing and evaluating the source. Instructors assign it to make you engage with sources before writing; researchers keep them as maps of a literature.
It's two skills stapled together: the citations (mechanical — we automate that) and the annotations (thinking — that part is yours, though here's exactly what to write).
The format
Each entry = a normal citation in your assigned style, then the annotation as a new indented paragraph beneath it. Entries stay alphabetized as in any reference list; the page keeps its usual title unless your instructor wants "Annotated Bibliography." Annotations run 100–200 words for most assignments.
Rasch, B., & Born, J. (2013). About sleep's role in memory. Physiological Reviews, 93(2), 681–766. https://doi.org/10.1152/physrev.00032.2012
In-text(Rasch & Born, 2013)
Build the citations first — free
What the annotation says
A strong annotation covers three moves in order: Summarize — the source's question and findings in two or three sentences. Assess — credibility and quality: the authors' standing, the method, the venue, limitations. Reflect — how it serves your project: what claim it will support, how it relates to your other sources.
Example annotation for the citation above: "Rasch and Born synthesize three decades of evidence that sleep actively consolidates memory rather than passively protecting it, with slow-wave sleep favoring declarative memory. As a Physiological Reviews article by the field's leading lab, it is the authoritative survey of the area. It anchors my literature review and supplies the mechanism my second section builds on, though its scope predates the 2015+ optogenetic work I cover separately."
Descriptive vs. evaluative annotations
Some assignments want descriptive annotations (summary only); most college work wants evaluative (summary + assessment + relevance). If the prompt says "critical" or "evaluative," the assess-and-reflect moves are where the grade lives. When unsure, write evaluative — it includes the descriptive.
The efficient workflow
- Generate each source's citation as you read it (generator — URL, DOI, or ISBN).
- Write the annotation immediately, while the source is fresh — three sentences beat reconstructing it later.
- Keep sources and notes together in a project — the notes field is built for exactly this.
- Export the alphabetized list from the Bibliography Builder, then paste annotations under each entry.
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Go Premium — $5/monthFrequently asked questions
- How long should each annotation be?
- Typically 100–200 words (4–8 sentences) unless specified. Descriptive-only assignments run shorter; critical annotations for graduate work can run a page.
- Is the annotation indented?
- Yes — the annotation is a new paragraph indented under its citation (in APA, indent the whole annotation 0.5"). The citation keeps its normal hanging indent.
- Annotated bibliography vs. literature review?
- The annotated bibliography treats sources one at a time, each in its own entry. A literature review synthesizes across sources into a narrative. The first is often a stepping stone to the second.
- Can I quote the source inside its annotation?
- Sparingly — a short phrase at most. The annotation should demonstrate your understanding, not the author's prose.