Let's break it down. A bibliography is a list of citations of resources. An annotation means that there is descriptive text added to the citation.
An annotated bibliography is a list of resources that includes the full citation of each resource followed by a summary or evaluation of each resource. The length of the summary/evaluation can be as long or as short as you want. You can write 1-2 paragraphs or 1-2 pages depending on the level of information you are trying to gather about the resource. It can also vary depending on whether or not it is for an assignment. Ask your professor if he or she has a desired length.
Many times, you will want to include an introductory paragraph to your annotated bibliography. The purpose of this paragraph is to introduce the reader to your topic.
What should I include in my summary/evaluation?
When you write your summary or evaluation of the resource, you want to convey a few basic ideas: relevance, accuracy, and quality of the sources cited. You are trying to inform the reader of your annotated bibliography and why it is or is not a good resource for your research project.
Ask yourself these questions:
Is the author of the resource knowledgeable and authoritative? Is the resource written for your purposes? Is it an academic resource? Something more for the general public? For children? Does this resource help the argument I am presenting in my research paper or project? Where did you find this information? In the library? In a database or on the web?
How do I write an annotated bibliography?
One way to assess your resources is to SKIM, this is not a close reading. You are just trying to get a snapshot of what is in the resource. For an article, get clues from the title, headings, chapter titles, read the first few sentences of each paragraph. When assessing a book, get information from major divisions of the book, from chapter titles, or subheadings in a chapter. Read the introductions and conclusions of each chapter for information.
You may want to do a more in-depth annotation and do a close reading of the resources.
Is an annotated bibliography the same as including an abstract?
No, an annotated bibliography is a critical look at a resource. An abstract is only a description and summary of the content. You want to summarize and assess your resource.
There are many great reasons to create an annotated bibliography.
Many professors assign annotated bibliographies as a way to help you start your research and get you thinking about the information you need to gather for your assignment.
Assessing and critically thinking about your resources helps you recognize what information is relevent to your argument, what information is current for your argument, and what information is authoritative on your argument.
When you are in the middle of the research process, it is helpful to take notes on the resources you find. You will be able to weed out the useless or irrelevant material and focus more on what is productive for your assignment.
By taking these notes (annotations), you can learn a lot about your topic. You can also help inform the reader of the quality of information you chose.
The document below is a sample annotated bibliography used with permission from Professor Nic Witschi who gives a good brief description of an annotated bibliography followed by an example formatted in MLA.