An annotated bibliography is a list of citations to books, articles, and documents. Each citation is followed by a brief (usually about 150 words) descriptive and evaluative paragraph, the annotation. The purpose of the annotation is to inform the reader of the relevance, accuracy, and quality of the sources cited.
Abstracts are the purely descriptive summaries often found at the beginning of scholarly journal articles or in periodical indexes. Annotations are descriptive and critical; they may describe the author's point of view, authority, or clarity and appropriateness of expression.
For guidance in critically appraising and analyzing the sources for your bibliography, see How to Critically Analyze Information Sources. For information on the author's background and views, ask at the reference desk for help finding appropriate biographical reference materials and book review sources.