A bibliography is an alphabetical list of selected sources. It may include books, journal or magazine articles, newspapers articles, audiovisual materials, web sites, to name just a few types of resources. The actual citation includes all information necessary for someone to find that exact resource: author, title, publisher, url, etc. This information is formatted according to a particular style as recommended by your professor. APA and MLA are two commonly used styles (see our research guide on Citing Sources for help). Your annotation for a particular work is added underneath its citation. It may simply be a comment, perhaps a few sentences, or one or more paragraph(s) as stipulated by your professor.
Here is a sample entry in an annotated bibliography which follows the MLA format for the citation:
Annotations in the Margins made to the work of Saint Augustine (Link)
An abstract is a short summary generally found in the beginning of scholarly articles and papers that inform potential readers of it's contents. It is descriptive only. Annotations may also be descriptive in part, however, they also include an evaluative or critical element as well. Annotations may focus on a variety of issues such as the work's hypothesis, scope, methodology, conclusion and/or the overall success of the author's argument.
A man and woman riveting team working on the "nuts and bolts" of the cockpit shell of a C-47 aircraft (1942) Link
Some aspects you may consider when preparing an annotated bibliography:
A descriptive annotation or the descriptive part of an annotation is essentially a summary of the work. The descriptive element of an annotation would summarize the work as a whole or discuss specific aspects related to the author(s) stated intention/purpose, methodology and/or conclusions.
A critical annotation or the critical component of an annotation presents your critique of the source in question and may include both positive and negative comments. For instance negative aspects of a critical annotation may discuss a noticeable tone or bias of the author, question the premise or accuracy of the work, or mention omissions that you believe may hinder the overall usefulness or validity of the work. Positive aspects of critically analyzing a work may mention the author(s) new approach to topic, an interesting and valuable conclusion, an insightful urging for future investigations on the topic.