A good annotation summarizes and evaluates each source. In the example below, notice how the student does the following:
* The citation below is in MLA style.
London, Herbert. "Five Myths of the Television Age." Television Quarterly 10 (1) Spring 1982: 81-89.
Herbert London, the Dean of Journalism at New York University and author of several books and articles, explains how television contradicts five commonly believed ideas. He uses specific examples of events seen on television, such as the assassination of John Kennedy, to illustrate his points. His examples have been selected to contradict such truisms as: "seeing is believing"; "a picture is worth a thousand words"; and "satisfaction is its own reward." London uses logical arguments to support his ideas which are his personal opinion. He doesn't refer to any previous works on the topic; however, for a different point of view, one should refer to Joseph Patterson's, "Television is Truth" (The Journal of Television 45 (6) November/December 1995: 120-135). London's style and vocabulary would make the article of interest to any reader. The article clearly illustrates London's points, but does not explore their implications, leaving the reader with many unanswered questions.
The above example is adapted from Memorial University Libraries' "How to Write Annotated Bibliographies."