An annotated bibliography includes a citation and a written statement about each work to help potential readers decide if an item is relevant to their interests. Most often they are arranged alphabetically by author, but they can also be arranged chronologically, or by topic. Most style manuals provide few details on how to write annotations. This guide only provides brief guidance. For more details see How to Prepare an Annotated Bibliography (created by Research & Learning Services, Olin Library, Cornell University Library, Ithaca, NY, USA and used with permission).
According to MLA Handbook for Writers of Research Papers (7th edition): “An annotated bibliography, also called Annotated List of Works Cited, contains descriptive or evaluative comments on the sources” (section 5.3.2)
For guidance on how to write and format annotated bibliography entries, see the Ask the MLA Style Center Annotated Bibliography page.
APA does not mention annotated bibliographies but instead gives directions for writing abstracts. According to the Publication Manual of the American Psychological Association (6th edition), an abstract is defined as "a brief, comprehensive summary of the contents of the article; it allows readers to survey the contents of an article quickly and, like a title, it enables persons interested in the document to retrieve it from abstracting and indexing databases." (p.25) The APA guidelines for authors writing their own abstracts may be helpful for students as well. The manual describes elements to include for specific types of reports and articles. See pages 26-27 for details.
According to Turabian, Kate L. A Manual for Writers of Research Papers, Theses, and Dissertations (8th edition) section 16.2.1: "Some writers annotate each bibliography entry with a brief description of the work's contents or relevance to their research..."
The Turabian (section 16.2.1) and Chicago manuals (section 14.59) offers two ways of using annotations. "If your annotations are brief phrases, add them in brackets after the publication data..." Examples from Turabian 7th edition:
"You may also add full-sentence annotations on a new line with paragraph indentation" (example from Turabian):
Only 2 styles automatically format annotated bibliographies: