Each entry in an annotated bibliography should include:
1) a citation
2) a brief summary of the article, including the writer's main argument
3) a brief discussion of how you might use the article in your paper
Summarize: Some annotations merely summarize the source. What are the main arguments? What is the point of this book or article? What topics are covered? If someone asked what this article/book is about, what would you say? The length of your annotations will determine how detailed your summary is.
Assess: After summarizing a source, it may be helpful to evaluate it. Is it a useful source? How does it compare with other sources in your bibliography? Is the information reliable? Is this source biased or objective? What is the goal of this source?
Reflect: Once you've summarized and assessed a source, you need to ask how it fits into your research. Was this source helpful to you? How does it help you shape your argument? How can you use this source in your research project? Has it changed how you think about your topic?
Your annotations don't necessarily have to include all three of these aspects but you need to at least summarize.
From: OWL at Purdue University
Holland, Suzanne. The Human Embryonic Stem Cell Debate : Science, Ethics, and Public Policy. Boston: MIT Press, 2001.
This is the annotation of the above source. In this example, I am following MLA guidelines for the bibliographic information listed above. If I was really writing an annotation for this source, I would now be offering a brief summary of what this book says about stem cell research.
After a brief summary, it would be appropriate to assess this source and offer some criticisms of it. Does it seem like a reliable and current source? Why? Is the research biased or objective? Are the facts well documented? Who is the author? Is she qualified in this subject? Is this source scholarly, popular, some of both?
The length of your annotation will depend on the assignment or on the purpose of your annotated bibliography. After summarizing and assessing, you can now reflect on this source. How does it fit into your research? Is this a helpful resource? Too scholarly? Not scholarly enough? Too general/specific? Since "stem cell research" is a very broad topic, has this source helped you to narrow your topic?
From: OWL at Purdue University