The Chicago Manual of Style presents two basic documentation systems, the Humanities style (notes and bibliography) and the Author-Date system. Choosing between the two often depends on subject matter and nature of sources cited, as each system is favored by different groups of scholars.
The Humanities style is preferred by many in literature, history, and the arts. This style presents bibliographic information in notes and, often, a bibliography. It accommodates a variety of sources, including esoteric ones less appropriate to the author-date system.
The more concise Author-Date system has long been used by those in the physical, natural, and social sciences. In this system, sources are briefly cited in the text, usually in parentheses, by author’s last name and date of publication. The short citations are amplified in a list of references, where full bibliographic information is provided.
The two dropdown pages provide some common examples of materials cited in both styles.
The Chicago and Turabian styles are nearly identical. The differences between the styles are mainly seen in how notes are numbered.
In Turabian style, use superscript 1 for endnote and footnote numbers in the text and at the beginning of each note.
In Chicago style, the note number in the text is in parentheses (1) and is followed by a period and space in the note, as in the following example:
Additional information on Chicago/Turabian style may be found at these websites:
Kate Turabian, the dissertation secretary at the University of Chicago for over 30 years, developed her guide for students and researchers writing papers, theses, and dissertations. Her manual is based on the University of Chicago Press's Manual of Style and departs from it in few places.
"Turabian," as her guide is called, synthesizes the rules most important for students' papers and other scholarly research not intended for publication, and omits some of the publishing details and options that "Chicago" provides.