Your syllabus says «follow proper citation style» without specifying which one. Sound familiar? Choosing wrong between Chicago, APA, and MLA costs you points on every paper. This guide cuts through the confusion with a definitive side-by-side comparison and discipline-by-discipline breakdown.
Chicago vs APA vs MLA: The One-Paragraph Summary
APA (American Psychological Association) uses parenthetical author-date citations and dominates the social sciences. MLA (Modern Language Association) uses parenthetical author-page citations and rules the humanities and literature. Chicago offers two systems: Notes-Bibliography (footnotes, used in history) and Author-Date (parenthetical, used in some sciences). If your professor didn’t specify, the discipline tells you which one to use.
Which Disciplines Use Which Style?
| Discipline | Standard Style |
|---|---|
| Psychology, education, social work, nursing | APA 7th edition |
| Sociology, communication, criminology | APA 7th edition |
| English literature, comparative literature | MLA 9th edition |
| Modern languages, film studies, cultural studies | MLA 9th edition |
| History, philosophy, theology | Chicago NB (Notes-Bibliography) |
| Art history, music, classics | Chicago NB |
| Political science, economics, linguistics | Chicago Author-Date or APA |
| Biology, chemistry, engineering | Vancouver, ACS, or IEEE (not these three) |
When in doubt: ask your professor. But if you’re choosing for a history course, use Chicago NB. For a psychology or social science course, use APA. For a literature or language course, use MLA.
In-Text Citations: Side-by-Side
Using the same source — a book by Jane Smith published in 2024, page 47 — here’s how each style cites it in-text:
| Style | Paraphrase | Direct Quote |
|---|---|---|
| APA | (Smith, 2024) | (Smith, 2024, p. 47) |
| MLA | (Smith 47) | (Smith 47) |
| Chicago NB | Footnote: Smith, Title, 47. | Footnote: Smith, Title, 47. |
| Chicago AD | (Smith 2024, 47) | (Smith 2024, 47) |
The key pattern: APA = author + year. MLA = author + page. Chicago NB = footnote (no parenthetical). Chicago AD = author + year + page (similar to APA but without commas after author).
Reference Page: Three Styles, One Source
Using the same source throughout — Jane Smith, Introduction to Research Methods, 3rd edition, Routledge, New York, 2024:
APA (References page)
Smith, J. (2024). Introduction to research methods (3rd ed.). Routledge.
MLA (Works Cited page)
Smith, Jane. Introduction to Research Methods. 3rd ed., Routledge, 2024.
Chicago NB (Bibliography)
Smith, Jane. Introduction to Research Methods. 3rd ed. New York: Routledge, 2024.
What to notice: APA uses the author’s initials and puts the year second. MLA and Chicago use the full first name. Chicago requires the publisher’s city; APA and MLA don’t. APA uses sentence case for the book title; MLA and Chicago use title case.
Document Format Comparison
| Feature | APA 7th | MLA 9th | Chicago 17th |
|---|---|---|---|
| Title page | Yes (student format) | No — header on p.1 | Yes |
| Abstract | Usually required | Not required | Rarely required |
| Running head | Not for students | Last name + page # | Not required |
| Footnotes for citations | No | No | Yes (NB system) |
| Reference page title | References | Works Cited | Bibliography |
| Heading levels | Formal 5-level system | Flexible | Flexible |
| Font / size | 12pt serif | 12pt serif | 12pt serif |
| Margins | 1 inch all sides | 1 inch all sides | 1 inch all sides |
| Spacing | Double | Double | Double |
The Angle Most Guides Miss: These Styles Reflect Different Values
The differences between these styles aren’t arbitrary — they reflect the intellectual priorities of each discipline.
APA’s author-date system signals that recency matters. In the social sciences, a 2018 study is less relevant than a 2024 one, so the year appears front-and-center in every citation. Readers can immediately assess whether research is current.
MLA’s author-page system signals that the text itself matters. In literary studies, you’re often tracking specific passages and analyzing language — so page numbers are more important than publication dates. A 400-year-old Shakespeare play is as relevant as a contemporary critical essay.
Chicago’s footnote system signals that depth and transparency matter. Historians cite primary sources, archival documents, and secondary interpretations simultaneously. Footnotes let scholars do all of this without cluttering the main argument. The endnote is a scholarly conversation running alongside the text.
When you understand why each style exists, the rules start to feel logical rather than arbitrary.
The Most Common Cross-Style Mistakes
- Using APA parenthetical citations in a Chicago NB paper — Chicago NB uses footnotes, not (Author, Year) parentheticals. This is the most common cross-contamination error.
- Calling the reference page «Bibliography» in an APA paper — APA calls it References. MLA calls it Works Cited. Chicago NB calls it Bibliography. Match the term to the style.
- Capitalizing article titles in APA — APA uses sentence case for titles in the reference list. Chicago and MLA use title case.
- Adding «p.» before page numbers in MLA — APA uses «p.» (Smith, 2024, p. 47). MLA just uses the number: (Smith 47). No «p.» needed in MLA.
- Using a title page in MLA — MLA student papers don’t have a separate title page. Use the four-line header on page 1 instead.
Download All Three Templates
Get pre-formatted Word documents for all three styles — no setup required:
- APA Format Template — Free Download
- MLA Format Template — Free Download
- Chicago Style Template — Free Download
Related Resources
- APA vs MLA: Detailed Comparison
- APA vs Chicago: Key Differences
- Reference List vs Bibliography
- How to Cite in APA