How to Write an Annotated Bibliography

What an annotated bibliography actually is

Cornell University Library defines it as a list of citations to books, articles and documents in which each citation is followed by a brief — usually about 150 words — descriptive and evaluative paragraph. That last word is the one students skip. An annotation isn't a summary; it's a summary plus a verdict.

It does two jobs at once:

• For the marker — it proves you read the sources and can tell a strong one from a weak one.
• For you — it is the working document your literature review gets written from. Done properly, the annotations already contain the review's paragraphs.

What goes in an annotation: four moves

A good annotation makes four moves in roughly this order.

1. What the source claims. The argument or research question, and the scope — one or two sentences, no more.
2. How it knows. The method, data, sample or archive. This is where a source's authority actually comes from.
3. How good it is, and where it sits. Its strengths and limits, and which other source on your list it agrees or disagrees with.
4. What it does for your project. The section or claim it supports. One sentence, and the most useful line you will write.

MLA is unusually direct about what to leave out: annotations should describe or evaluate sources, and should not rehash minor details, cite evidence, quote the author, or recount the steps of an argument. If your annotation reads like a shrunken version of the paper, you've written the wrong thing.

Descriptive or critical?

A descriptive (or informative) annotation reports what the source contains. A critical (or evaluative) annotation also judges it — its credibility, its limitations, its usefulness to you. Most assignments want the second, and most students hand in the first. If the brief doesn't say, write critically: it's the harder, safer option.

A weak annotation, then a strong one

Same source both times:

Sword, H. (2012). Stylish academic writing. Harvard University Press.

Weak:

This book is about academic writing. Sword argues that academic writing is often bad and gives lots of examples. It was published by Harvard University Press. It is a useful book for my topic.

No method, no judgment, no use — and "published by Harvard" is doing the work that evidence should be doing. Now the same source annotated properly:

Strong:

Sword examines the gap between how academics describe good writing and the prose they actually publish, drawing on an analysis of more than a thousand peer-reviewed articles across a wide range of fields. That corpus is the book's strength: the argument rests on documented patterns rather than on one scholar's taste, and the chapters on titles, openings and headings are immediately usable. Because the sample is drawn from published articles, however, it says more about what stylish prose looks like than about how writers produce it — for the process side it needs pairing with Boice's work on writing habits. I'll use it in the section arguing that disciplinary convention and readability pull in opposite directions.

Roughly 130 words, and every sentence earns its place: claim, evidence base, limitation, and a stated use.

Formatting in APA 7

• Order entries alphabetically by the first author's surname, exactly as in a reference list, with the usual hanging indent.
• Start the annotation as a new paragraph below its reference entry, with the whole annotation indented 0.5 in from the left margin.
• Do not add an extra indent to the annotation's first line. If an annotation runs to more than one paragraph, indent the first line of each subsequent paragraph a further 0.5 in.
• Double-space throughout, like the rest of an APA paper.

APA deliberately says nothing about how long an annotation should be or what it must contain — the manual leaves the number of sources, the length and the focus to your instructor. Formatting is APA's business; content is your brief's.

Formatting in MLA 9

• Style each entry exactly as you would in a works-cited list, then append the annotation.
• Title the page Annotated Bibliography or Annotated List of Works Cited.
• Indent the annotation one inch from the margin, so it's visibly distinct from the entry's half-inch hanging indent. Double-space it, with no extra gap between the entry and its annotation.
• Keep it to one paragraph where you can; if you need several, indent each one and don't add extra space between them.
• Entries may be arranged alphabetically, by date of publication, or by subject.

The same source, in MLA 9:

Sword, Helen. Stylish Academic Writing. Harvard UP, 2012.

Note Harvard UP — MLA abbreviates "University Press" to UP in the publisher position.

Formatting in Chicago

Chicago is the flexible one. The Chicago Manual of Style (17th ed., 14.64) states that annotations may simply follow the publication details — sometimes in brackets, if only a few entries are annotated — or they may start a new line, and are often indented from the left margin. Both are correct, which means the real rule is consistency: pick one pattern, use it for every entry, and ask your instructor if the brief has a preference.

A workflow that doesn't eat your week

1. Screen before you read. Abstract and conclusion decide whether a source is in. Most aren't.
2. Read for the four moves. Introduction, method, conclusion — in that order — with the four questions above in front of you.
3. Annotate the same day. A source read on Monday and annotated on Friday gets a vaguer, worse note.
4. Always write the "I'll use it for" line. Collected together, those lines are your literature review outline.
5. Alphabetise last. Sorting as you go wastes time you could spend reading.

The rule that outranks every formatting rule

Every entry must be a source you actually opened. An annotated bibliography is the assignment where fabricated references are easiest to catch, because the annotation has to say something specific about a method and a limitation — and an invented source has neither. If a chatbot suggested a title, find it, open it, and confirm it exists before it goes on the list; language models invent realistic-looking references as a matter of course.

Frequently asked questions

Keep reading

• How to Write a Literature Review Without Fabricating Sources
• How to Search Google Scholar Effectively
• Systematic Review vs Scoping Review vs Literature Review
• Free Citation Generator (APA, MLA, Chicago, Harvard, IEEE)