An annotated bibliography is a list of sources that includes not only publication information, but also a brief summary, analysis, or evaluation of each source. This additional information is called an annotation.

The purpose and scope of annotations varies, so be sure you understand what kinds of information your instructor expects you to provide in each annotation. Purpose often dictates length; the more comprehensive or detailed the information required, the longer the annotation. Some annotations require only one or two sentences; others may demand a substantial paragraph. Again, check with your instructor to be sure you understand their expectations.

The following process will assist you in compiling an annotated bibliography. 

1. Research:

The most important step in compiling an annotated bibliography is finding appropriate sources. When choosing materials to include in your bibliography, consider both the relevance and the reliability of each source.

Relevance

• Will you be able to use this source for your essay? 
• Does it comment directly on your research question? 

As you research, you may find that some of the sources you find are on your topic but don’t come at it from quite the right angle. Try to find many more sources than you need in this first stage so that you can discard them when you need to. 

Reliability

• Does this source come from an obviously reputable place? 

For formal articles, a common measure for reputability is whether or not the source is peer-reviewed. You can find this information by researching the article’s source of publication. Also, if searching on a database like those provided by the library or Google Scholar, you can usually filter by whether or not a source is peer-reviewed. When scholarly works are not required or expected, you should carefully research non-academic sources for reputation and bias.

Give yourself enough time

Make sure that you have several days of leeway for accessing your sources. When accessing scholarly sources, you may find that you need to wait a few days to access electronic sources that need to be checked out to you, or even a few weeks for print sources.

2. Read:

Finding materials is only half the battle

Once you identify appropriate sources, you must read them. You’ll have to understand the structure, purpose, scope, and content of each source. As you read, take notes, recording the main points and relevant details. To save time when preparing citations, include page numbers in your notes.

Allot your time carefully

You won’t be happy to have read an entire source and then realized you couldn’t use it. Information related to relevance is most likely to be in the introduction or conclusion, so check those sections first and evaluate whether the source meets your needs.

Note that a source may still be usable even if it seems to counter your argument

Including such sources in your thinking and in your discussion is likely to enrich your conclusions. For more information on this topic, you may wish to reference our resource on counterargument.

3. Compose:

Although, as mentioned earlier, any given professor may have different expectations for what kind of content should go into your annotations, common elements include the following:

A description of the source, including the overall concept and conclusions as well as any other relevant details

A basic element included in most annotations is a summary of the source being discussed. This gives the reader an idea of what the source is and may give an idea as to how it will be used. It also helps to contextualize any other details that may be provided in the annotation.

An explanation of how the source will be used in the paper and/or relates to the research question

Often, the point of an annotated bibliography is to build a set of sources for a paper. As such, an important element in an annotation is discussing why the source is useful for the paper.

• Does the source provide a novel idea not included in other sources?
• Does it disagree with your thesis in a way that you plan to address?
• Does it provide a definition that you plan to use?

Make the purpose of the source's inclusion in the bibliography clear.

Connection between the source and other sources included in the bibliography

A strategy to make your annotated bibliography more robust is to draw connections between sources, specifically noting similarities and differences. This can be useful for both you and your readers in clarifying the relationships between your sources and what variety of perspectives your bibliography represents.

Additional notes

Prepare your bibliography according to the appropriate citation style guide. Include the annotation immediately following each entry in the bibliography. Check your annotations after you’ve written them to ensure that they cover all the required information. If you have multiple annotations, consider making the order of information different in each. Varying your paragraph’s structure keeps your annotations from sounding repetitive or “copied and pasted.” Also, ensure your annotated bibliography covers a decent amount of information on your research question overall.

Example (using the APA citation style):

Marshall, J. M., & Hay, B. A. (2014). Medusa: A novel gene drive system for confined suppression of insect populations. PLoS ONE, 9(7), 1–13. https://doi.org/10.1371/journal.pone.0102694

"Medusa: A Novel Gene Drive System for Confined Suppression of Insect Populations" fills a gap in this bibliography, in that it covers a method for insect population control through gene driving that is limited to local environments and so avoids diverse and potentially contradictory regulations on gene driving and on insect population controls across borders. Specifically, Marshall and Hay propose a gene-driving system called Medusa, which involves altering both the Y and X chromosomes of male insects which, when released into the wild, mate with females and share those chromosomes with their offspring. As a result of the alterations, female offspring would be less likely to be successful, causing a drop in the entire population of the insect. The authors claim this system is both reversible and repeatable, making it remarkably sustainable, at least in theory. Notably, the article does not include an actual trial of the gene driving method proposed; as such, it may include some flaws which are not obvious in this but which would be in practice. As such, while I may propose it as a potential solution to insect population control in the paper, it will be important to contextualize it as more conceptual than proven.