CASRAI Dictionary

Tag: Chicago style

  • Chicago and Vancouver Referencing Styles Explained

    Chicago style is the referencing system of The Chicago Manual of Style (17th edition), offering two variants — notes-bibliography, which uses footnotes or endnotes, and author–date, which uses parenthetical citations. Vancouver style, codified in the ICMJE Recommendations, is a numeric system in which sources are numbered in the order they first appear and listed in that numeric order. Chicago dominates history, the arts and publishing; Vancouver is standard across medicine and the biomedical sciences.

    These two styles bracket the range of approaches a researcher will meet. Chicago is the most flexible of the major systems; Vancouver is the most compact. Seeing them side by side clarifies why a discipline chooses one referencing logic over another — a theme we develop in our broader comparison of APA, MLA, Chicago and Vancouver.

    Chicago notes-bibliography

    In the notes-bibliography variant, a superscript number in the text points to a footnote (or endnote) carrying the full source details, and a parallel bibliography at the end lists all sources alphabetically. The note and bibliography entry differ slightly in format. A first footnote gives full detail:

    1. Jane Smith, Foundations of Research Integrity (London: Academic Press, 2019), 142.

    The matching bibliography entry inverts the author’s name and uses full stops rather than commas and brackets:

    Smith, Jane. Foundations of Research Integrity. London: Academic Press, 2019.

    Subsequent references to the same work are shortened to author, short title and page — Smith, Foundations, 88 — which keeps the notes readable. This variant suits the humanities because footnotes can carry commentary as well as citations, letting a historian discuss a source without breaking the main argument.

    Chicago author–date

    The author–date variant works much like APA: a parenthetical (Smith 2019, 142) in the text points to an alphabetical reference list. It is favoured in the sciences and social sciences when Chicago is the house style. The reference-list entry resembles the bibliography entry but moves the year forward: Smith, Jane. 2019. Foundations of Research Integrity. London: Academic Press. Choosing between Chicago’s two variants is normally dictated by your discipline or publisher, not personal preference.

    Vancouver and the ICMJE Recommendations

    Vancouver style assigns each source a number the first time it is cited, in brackets or as a superscript — [1] or 1 — and reuses that number on every later citation of the same source. The reference list is then ordered numerically, by order of first appearance, not alphabetically. The ICMJE Recommendations specify the format, including abbreviated journal titles and a distinctive author style with no full stops after initials:

    1. Smith J, Jones R. Open-access uptake in clinical trials. J Res Stand. 2021;14(3):220–38.

    Vancouver’s numeric compactness suits biomedical papers, which often carry dozens of references and value an unobtrusive in-text marker. Because the numbering follows appearance order, inserting a new citation mid-draft renumbers everything after it — which is why reference-manager software is near-universal in the field.

    Comparing the three at a glance

    Feature Chicago notes-bib Chicago author–date Vancouver
    In-text marker Superscript note number (Author Year, page) Bracketed number [1]
    List order Alphabetical bibliography Alphabetical reference list Numeric, by first appearance
    Typical disciplines History, arts, publishing Sciences, social sciences Medicine, biomedical sciences
    Governing standard Chicago Manual 17th ed. Chicago Manual 17th ed. ICMJE Recommendations

    Why the differences matter

    The choice of system is not arbitrary decoration. A footnote system lets a humanities scholar annotate and qualify a source in place; a numeric system lets a clinician cram a dense evidence base into a tight word limit; an author–date system keeps the year visible where recency is part of the argument. Each encodes a different relationship between the writer’s text and the scholarly record. Underneath all of them, the obligations to assign credit accurately and to record authorship honestly are the same — only the surface format changes.

    If you are moving between disciplines and meeting an unfamiliar style, CASRAI’s guidance for authors can help you map an output onto whichever convention a new editor requires.

    Frequently asked questions

    Is Chicago author–date the same as APA?

    They are close cousins but not identical. Both use author–date in-text citations and an alphabetical list, but punctuation, capitalisation and the treatment of titles differ. Chicago title-cases titles and has its own publisher conventions; APA uses sentence case for article titles. Always follow the specific manual your editor names.

    How does Vancouver handle a source cited several times?

    It keeps the original number. A source numbered [3] on first appearance is cited as [3] every subsequent time, and appears once in the reference list at position 3. The number is fixed to the source, not to the location of the citation.

    When should I use notes-bibliography rather than author–date Chicago?

    Use notes-bibliography in the humanities and wherever footnotes are expected to carry discussion as well as citations. Use author–date in the sciences and social sciences, or wherever a journal’s house style specifies it. The decision is set by the publisher, not the writer.

    Do these styles require DOIs?

    Both increasingly expect a DOI where one exists, and the ICMJE Recommendations encourage including it for journal articles. A DOI anchors the entry to a persistent address, which matters as much in numeric and notes systems as in author–date ones.

  • Footnotes and Endnotes in Academic Writing

    Footnotes are notes placed at the bottom of the page, marked by a superscript number in the text; endnotes collect the same notes together at the end of a chapter or document. Both are central to note-based citation styles such as Chicago notes-bibliography and Oxford (OSCOLA-influenced) referencing, common in history, law and the humanities.

    This guide explains how notes work, the difference between citation and content notes, and when to choose notes over an author-date system.

    Footnotes versus endnotes

    The mechanism is identical — a superscript number in the text points to a numbered note — but placement differs:

    • Footnotes sit at the foot of the same page, so the reader can glance down without losing their place. Preferred where notes are frequently consulted.
    • Endnotes gather at the end, keeping the page clean. Preferred for note-heavy texts where footnotes would crowd the layout.

    Numbering usually runs continuously through a chapter or the whole work. The choice is often set by the publisher’s house style rather than the author.

    Citation notes versus content notes

    Notes do two distinct jobs, and good practice keeps them clear:

    • Citation notes give the source: author, title, publication details and page. They replace the parenthetical (author, year) of author-date styles.
    • Content notes add commentary, a caveat, a translation or a tangent that would interrupt the main argument if left in the body text.

    A full citation note in Chicago notes-bibliography looks like this on first appearance:

    1. Jane Smith, Designing the Research Question (London: Academic Press, 2020), 114.

    Subsequent references to the same work are shortened:

    2. Smith, Designing the Research Question, 121.

    Chicago notes-bibliography and Oxford style

    Chicago offers two systems: author-date (similar in spirit to Harvard referencing) and notes-bibliography, the note-based variant described here. Oxford style, widely used in UK humanities and the basis of much legal referencing, follows the same note-and-bibliography logic with its own punctuation. Both pair numbered notes with a full bibliography at the end, alphabetised by author.

    Element First footnote Bibliography entry
    Author order Forename Surname Surname, Forename
    Punctuation Commas, parentheses Full stops
    Page Specific page cited Whole-work range or none

    When to use notes instead of author-date

    Note-based styles suit work that:

    • Cites many primary sources, archives or legal materials whose full details do not compress neatly into (author, year);
    • Needs frequent discursive commentary alongside citations;
    • Follows a humanities or legal house style that expects notes.

    Author-date systems suit the sciences and social sciences, where the year of publication is immediately relevant and brevity in the body text is prized. For the numeric alternatives used in technical and clinical writing, see IEEE and AMA citation styles explained, and for the broader landscape, citation styles compared.

    Formatting good notes

    Keep superscript markers at the end of the relevant clause, after punctuation in most styles. Avoid stacking several markers on one word. Use shortened forms after the first full citation, and reserve content notes for material that genuinely cannot sit in the body. Our for authors guidance covers consistency checks before submission, and our practitioner guide to citing sources covers the underlying principles.

    How notes fit the research record

    Whatever the citation mechanism, the goal is an unambiguous, traceable record. Controlled terms in our dictionary and contributor roles via CRediT complement careful notes by structuring the rest of a work’s metadata. See more in research outputs.

    Frequently asked questions

    Should I use footnotes or endnotes?

    Follow your publisher or department. Footnotes aid readers who consult notes often; endnotes keep pages uncluttered in note-heavy texts.

    Do I still need a bibliography if I use footnotes?

    In Chicago notes-bibliography and Oxford style, yes — the notes give running citations and the bibliography gives the full alphabetised list.

    Can a footnote contain both a citation and a comment?

    It can, but separating citation notes from content notes keeps the apparatus clearer. Use comments sparingly.

    Are footnotes outdated?

    No. They remain standard in history, law and many humanities fields where discursive commentary and primary-source citation are essential.