What Is an Annotated Bibliography? Purpose, Types, and Format

Academic Writing updated on  May 31, 2024 6 min read

Most people know what a bibliography is—a list of sources at the end of a document. But what does it mean for it to be annotated? An annotated bibliography is a list of sources along with the compiler’s comments on each one.

Each reference gives complete citation information for the source and includes a single-paragraph comment, also called an annotation, at the end.

Why write an annotated bibliography?


Students and researchers compile annotated bibliographies as part of an information-gathering process. For example, students might write one as they’re collecting sources for a research paper or dissertation. Scholars might write one to save other researchers the time and effort of looking through many sources.

This compilation of sources meets some or all of the following goals:

  • Summarize the body of knowledge on a subject
  • Compare and contrast sources
  • Inform or guide other researchers


Besides accomplishing the goals above, you have a few things to gain by writing an annotated bibliography.

  • It helps you to evaluate the quality of sources more comprehensively. When writing annotations, you must critically analyze a source rather than just scanning or reading it. Putting in this effort makes you more informed about your topic and empowers you to choose sources that strengthen your research.
  • It shows your instructor that you’ve taken a deep dive into the sources. As a student, you may need to summarize or evaluate a source to write your annotated bibliography well. By summarizing a source, you show that you have read and understood it, whereas  by evaluating it, you show that you understand the source well enough to form and articulate new views about it.
  • It raises your credibility in your field. Scholars who have read deeply and widely on a topic and can offer knowledgeable opinions become sources of knowledge and insight in and of themselves. Their annotated bibliographies may be published as standalone works or as part of a larger review of a topic.

Another way to raise your grade or your credibility is to make sure your annotated bibliography, like any other piece of academic writing, is error free. Our Grammar Checker is a helpful proofreading tool.

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What are the types of annotated bibliographies?

The type of annotated bibliography a scholar writes depends on which of the above goals they are aiming to achieve. Some annotations simply summarize the sources, while others offer a deeper analysis and the writer’s own views. These are some questions you might ask to improve your writing in either case:


What question or problem did this source try to address?
What methods did the study use to answer the question or solve the problem?
What are the study’s main findings?
What does the study’s author want the reader to know?
What are the study’s main contributions and limitations?


How does this study compare to others on the topic?
How reliable are this study’s findings?
How does this source contribute to your argument or research?

How is an annotated bibliography different from an abstract or a literature review?

Annotated bibliography vs. abstract

An annotated bibliography and an abstract are similar in that they may both summarize a source. However, an abstract appears at the beginning of a source, while an annotated bibliography appears at the end of a source with citations. Even if your annotated bibliography is meant only to summarize and not to analyze, copying the source’s abstract is plagiarism.

Summarizing a source in your own words is vital to maintaining academic integrity. One ethical way to do it is to try QuillBot’s Summarizer, which can help you pull the main ideas out of a longer text. Then our Paraphraser can offer you a ton of words and phrases to choose from so you can avoid paraphrasing plagiarism.

Annotated bibliography vs. literature review

An annotated bibliography is like a literature review because it reviews a variety of sources on the same topic. Both may offer the writer’s opinions and comments about the quality of the sources or be elements of a longer paper.

On the other hand, the two are different because an annotated bibliography offers commentary on one source at a time, while a literature review combines multiple sources’ viewpoints and the author’s own perspectives into a discussion. An annotated bibliography is laid out like a list of paragraphs, each beginning with full source citation details, with no transitions connecting them. However, a literature review focuses more on the flow of an argument over several paragraphs. Rather than giving complete citations, it denotes sources using minimal information, such as numbers or the author’s last name and publication year, to avoid distracting from the argument.

Whether you’re writing an annotated bibliography or a literature review, a plagiarism checker is a great way to double-check your work and avoid the consequences of plagiarism. The QuillBot Plagiarism Checker is easy to use.

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What is the usual annotated bibliography format

In general, every annotated bibliography should display an academic writing style, be alphabetized, and be extremely concise. When it comes to the specifics, though, the format of an annotated bibliography usually depends on the style guide the writer is following. These are some of the most frequently used style guides in many fields of study:

  • APA (American Psychological Association): social and natural sciences, business, economics, education;
  • MLA (Modern Language Association): English and other languages, humanities;
  • CMOS (Chicago Manual of Style) or Turabian: humanities, business, history;
  • AMA (American Medical Association): medicine;
  • CSE (Council of Science Editors): biology, botany, medicine;
  • Harvard: social and natural sciences, business, humanities, economics, medicine.

In nearly every style, you’ll need to use a hanging indent, meaning only the first line of an entry is not indented. Some styles call for beginning the annotation on the same line where the reference ends, and others ask writers to start it on a new line. Your instructor may provide an annotated bibliography template that shows the correct formatting and style.

QuillBot’s Citation Generator is not limited to the common style guides mentioned above. It can help you cite sources according to hundreds of style guides, from Academy of Management Review style to Zwitscher-Maschine referencing.

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What would an annotated bibliography example look like

Here’s a short example of an annotated bibliography in Chicago style. The first entry contains a summary annotation, while the second offers more comparison and analysis. (This is for example purposes only. All annotations should be the same type in your annotated bibliography.)

Fictional Representations of Mental Health in Young People

Plath, Sylvia. The Bell Jar. New York: Harper & Row, 1963.

This semi-autobiographical work describes a talented college student’s struggle with the expectations of a patriarchal society as she begins her adult life and career. In a conventional first-person narrative style and in the bildungsroman or coming-of-age genre, Esther Greenwood looks back years later and shares her feeling of detachment from reality, suicide attempt, successful treatment, and return to college. The story’s major themes include depression, sexual discovery, social expectations, idealism, and identity.

Salinger, J. D. The Catcher in the Rye. New York: Little, Brown and Co., 1951.

This novel details high school student Holden Caulfield’s struggle to meet societal expectations, particularly those of his parents, peers, and educational institutions, in a first-person stream-of-consciousness narration. It shares The Bell Jar’s genre, setting, and major themes as well as numerous plot similarities but narrates from a younger, male perspective with an even more casual tone. Further, while Esther Greenwood ends her story with optimism, the title The Bell Jar focuses on the symbolism of her entrapment. Conversely, when Caulfield concludes his story, he is still cynical and mostly unchanged, but the title The Catcher in the Rye optimistically focuses on who he wants to be. Both works reflect the damaging effects of rigid gender roles and the societal pressure to conform on young people’s mental health.

Formatting your annotated bibliography is no big deal when you use our QuillBot Flow, which integrates all the writing tools above with even more helpful features.

What are some tools for success?

When you started reading, you may have been intimidated by the idea of writing an annotated bibliography, but with our easy-to-follow overview and easy-to-use tools, you’ve got everything you need to succeed.

What are the 3 parts of an annotated bibliography?

An annotated bibliography is made up of:
(1) a title that clearly tells the reader its focus
(2) full citation information for each source
(3) a paragraph of commentary on each source.

How long should an annotated bibliography be?

Each entry in an annotated bibliography usually consists of just a few sentences, in the range of 100–300 words. The number of entries depends on the bibliography’s purpose and your instructor’s or publisher’s requirements. For example, a standalone annotated bibliography may be a dozen or more pages long, while an annotated bibliography for a student research paper may be only a page or two.


Hannah Skaggs

Along with Meredith Harris

Hannah, a writer and editor since 2017, specializes in clear and concise academic and business writing. She has mentored countless scholars and companies in writing authoritative and engaging content.

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