4.5 Chicago Documentation and Choosing a Citation Style
Key Takeaways
- The College Board outline names MLA, APA, and Chicago, so Chicago mechanics are directly testable on this exam.
- Chicago offers two systems: notes-bibliography, used in history and the humanities, and author-date, used in the sciences and social sciences.
- A Chicago note uses a superscript number in the text and a numbered note with first-name-first author order and parenthetical publication data.
- In the bibliography the author is inverted, elements are separated by periods, and entries are alphabetized with a hanging indent.
- Citation style is determined by discipline and by the assignment, never by writer preference, and mixing systems within one paper is an error.
4.5 Chicago Documentation and Choosing a Citation Style
College Board's content outline for this exam lists documentation of sources "including MLA, APA, and Chicago Manual of Style." Chicago is therefore fair game, and it is the style most candidates have never used. It is also structurally different from the other two: Chicago is not one system but two.
The current edition is The Chicago Manual of Style, 18th edition (2024). Many courses still assign the 17th edition (2017); the systems are identical and only details differ, and CLEP items test the systems rather than edition minutiae.
Two Systems, One Manual
| System | Used in | In-text mechanism | End matter |
|---|---|---|---|
| Notes–Bibliography | History, literature, art history, philosophy, theology | Superscript number → footnote or endnote | Bibliography |
| Author–Date | Sciences, social sciences, some business fields | Parenthetical (Author Year, page) | References |
A paper uses one or the other, never both. When a question says "Chicago style" without qualification in a humanities context, notes–bibliography is intended.
Notes–Bibliography Mechanics
A superscript numeral follows the punctuation of the sentence or clause being documented. The numeral points to a note at the foot of the page or at the end of the paper.
First (Full) Note
Author's name in normal order, title, publication data in parentheses, then the page cited — separated by commas:
- Jill Lepore, These Truths: A History of the United States (New York: W. W. Norton, 2018), 412.
Journal article:
- Amara Osei, "Rural Broadband and Clinical Access," Journal of Health Policy 46, no. 3 (2023): 217.
Subsequent (Shortened) Note
After the first full note, later citations of the same work use a shortened form: last name, short title, page.
- Lepore, These Truths, 519.
Chicago prefers this shortened form over Ibid., which the 17th edition already discouraged and which the 18th edition continues to treat as optional at best.
Bibliography Entry
The bibliography inverts the author's name, replaces the commas with periods, drops the parentheses, and gives the full page range for an article:
Lepore, Jill. These Truths: A History of the United States. W. W. Norton, 2018.
Osei, Amara. "Rural Broadband and Clinical Access." Journal of Health Policy 46, no. 3 (2023): 205–24.
Entries are alphabetized by author's last name with a 0.5-inch hanging indent.
What Changed in the 18th Edition
| Element | 17th edition | 18th edition |
|---|---|---|
| Place of publication for books | Required (New York: W. W. Norton, 2018) | No longer required (pre-1900 books give the city in place of the publisher) |
| Authors listed in a bibliography entry | Up to ten | Up to six; more than six → first three plus et al. |
| Authors listed in a note or author-date citation | Up to three | Up to two; more than two → first plus et al. |
| Page range for a chapter in an edited book | Required in the bibliography | No longer required |
Author–Date Mechanics
In-text: (Author Year, page) — note the comma before the page and the absence of "p."
Broadband subsidies preceded a measurable rise in telehealth use (Osei 2023, 217).
Reference list: the year moves forward, immediately after the author.
Osei, Amara. 2023. "Rural Broadband and Clinical Access." Journal of Health Policy 46 (3): 205–24.
The Three Styles Side by Side
| Feature | MLA 9 | APA 7 | Chicago 18 (notes–bib) |
|---|---|---|---|
| In-text form | (Lepore 412) | (Lepore, 2018, p. 412) | Superscript ¹ → note |
| End-matter title | Works Cited | References | Bibliography |
| Author name in list | Lepore, Jill | Lepore, J. | Lepore, Jill |
| Article title | "In quotation marks," title case | In sentence case, no quotation marks | "In quotation marks," title case |
| Date position | Late in the entry | Immediately after the author | End of the entry |
| Primary disciplines | Literature, languages, cultural studies | Psychology, education, nursing, business | History, art history, philosophy |
Fast identification on the exam: a year in parentheses right after the author means APA. A bare page number with no comma means MLA. A superscript numeral or a first-name-first author in a numbered note means Chicago.
Choosing a Style
Style is dictated, not chosen:
- The assignment governs. If the syllabus names a style, that is the answer.
- Otherwise the discipline governs. Humanities → MLA or Chicago notes; social and natural sciences → APA or Chicago author–date.
- The journal or publisher governs for work submitted for publication.
- Personal preference never governs, and neither does convenience.
Consistency Is the Testable Rule
Whatever the style, the fatal error is inconsistency. A paper that cites (Smith 42) in one paragraph and (Smith, 2019, p. 42) in the next has mixed systems. On CLEP items, an option that "correctly" formats one entry in a style different from the rest of the paper is wrong precisely because it breaks consistency.
Three further rules hold across all three styles and are the ones most likely to be tested directly:
- Every in-text citation must have a matching end-matter entry, and every end-matter entry must be cited in the text.
- Entries are alphabetized by the author's last name, or by title when no author is given.
- Hanging indents apply to the Works Cited, References, and Bibliography alike.
Which citation is formatted as a first full note in Chicago notes-bibliography style?
A student has already cited Jill Lepore's These Truths in full in note 1 and now cites page 519 of the same book in note 3. What does current Chicago style prefer?
A student is writing a research paper for an upper-level history seminar whose syllabus specifies no citation style. Which style is most appropriate, and why?