How to Write an Annotated Bibliography in APA Format
An annotated bibliography is a reference list where each citation is followed by a short paragraph — the annotation — that summarizes and often evaluates the source. It's a common assignment because it proves you actually read and thought about your sources. Here's how to format and write one in APA style.
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Open the Citation GeneratorFormatting rules
- Each entry starts with a normal APA reference (hanging indent, alphabetical order — all the usual reference page rules apply).
- The annotation starts on a new line below the reference, indented 0.5 inch from the left margin (the whole paragraph, like a block quote).
- Double-space everything; no extra line between the reference and its annotation.
- Unless told otherwise, annotations run one paragraph of roughly 100–200 words.
Three types of annotation
1. Summary (descriptive)
What is the source about? Main argument, methods, findings. Most assignments want at least this.
2. Evaluation (critical)
How good is it? Strengths, weaknesses, credibility of the authors, quality of the evidence.
3. Reflection (application)
How will you use it? Where it fits in your research project or argument.
Many instructors expect all three movements in each annotation: summarize → evaluate → reflect. Check your assignment brief.
A complete example
This comprehensive review synthesizes three decades of research on the relationship between sleep and memory consolidation. The authors argue that slow-wave sleep supports the consolidation of declarative memories while REM sleep primarily benefits procedural and emotional memory. The review's principal strength is its breadth — over 900 studies are integrated — though its length can overwhelm readers seeking a quick overview, and some sections predate recent optogenetic evidence. As a foundational source, it will anchor the literature review section of my research paper on study habits and sleep, particularly the claim that memory benefits accrue most strongly in the first sleep cycles after learning.
Useful academic verbs for annotations
Vary your openings: the authors argue, demonstrate, examine, synthesize, challenge, quantify, propose, document, question, contend. Avoid starting every annotation with "This article is about…".
Common mistakes
- Writing an abstract-style summary with no evaluation when the assignment asks for critique.
- Forgetting the annotation indent — it should align with the hanging indent, clearly grouped under its reference.
- Quoting heavily — annotations should be in your own words.
- Alphabetizing incorrectly; the order rules are identical to a normal reference list.
How many sources do I need?
Follow your assignment brief — typical annotated bibliographies run 5–20 sources. Quality of selection matters more than quantity: a mix of foundational works, recent peer-reviewed studies, and (where appropriate) authoritative reports shows breadth. If your instructor set a per-annotation word count, treat it as a hard limit; concision is part of the skill being graded.