How to Write an Annotated Bibliography (APA, MLA, Chicago)

Short answer: An annotated bibliography lists full citations, each followed by a 100–200 word annotation that summarizes the source, assesses its credibility, and explains its relevance to your project.

Annotations are graded on evaluation, not summary. Every entry should end with a sentence about how the source fits your argument.

The Three Annotation Types

1. Descriptive: summarizes scope and main findings only
2. Evaluative: adds an assessment of methodology, bias, and authority
3. Reflective: adds how the source will be used in your project (most commonly required)

What Each Annotation Should Cover

1. The author's credentials and the source's purpose
2. Method, sample, and scope of the study
3. Main findings or argument in one or two sentences
4. Strengths and limitations
5. Relevance to your research question

Style Formatting Differences

1. APA: hanging-indent reference, annotation indented 0.5 inches as a new block
2. MLA: Works Cited entry, annotation indented one inch, new paragraph
3. Chicago: bibliography entry, annotation single-spaced and indented

How to Choose the Right Topic

Step 1. Collect and cite sources in the required style first.

Step 2. Skim each source for purpose, method, and key finding.

Step 3. Draft a two-sentence summary, then two sentences of evaluation.

Step 4. Add one sentence linking the source to your thesis.

Step 5. Alphabetize the entries and check citation formatting.

Common Mistakes to Avoid

• Picking a topic so broad you cannot cover it in the assigned page count


• Choosing a subject with no credible, peer-reviewed sources available


• Restating an argument without adding your own analysis or evidence


• Ignoring your instructor's rubric, required citation style, or page limits


• Leaving topic selection until the night before the deadline

Frequently Asked Questions

How long should each annotation be?

Usually 100–200 words unless your rubric specifies otherwise. Consistency across entries matters.

Do annotations use first person?

Reflective annotations often do ("I will use this source to…"), but check whether your instructor permits first person.

Is an annotated bibliography the same as a literature review?

No. Annotations evaluate sources one at a time; a literature review synthesizes them into themes.

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