Author–Date System
A citation family that identifies sources in text by author surname and year of publication.
The author–date system places a short reference in the running text — usually surname, year, and page — with the full details in an alphabetical reference list at the end. APA, the Chicago author–date variant, and Harvard-style guides all belong to this family.
Its advantage is currency: readers see immediately how recent a source is, which matters most in fields where evidence ages quickly. That is why the sciences and social sciences adopted it while literary studies kept footnotes.
The mechanics are strict. Every in-text citation must correspond to exactly one reference-list entry, disambiguated where necessary by letters (2019a, 2019b) when one author published more than once in a year.
Common mistake: mixing systems inside one document — a footnote here, a parenthetical there. Choose one and apply it throughout; editors treat inconsistency as an error even when every individual citation is complete.
“Attention decays sharply after the first minute of reading (Nielsen, 2008, p. 14).”
Keep reading the glossary
An in-text source reference given in parentheses, keyed to a fuller entry in the bibliography.
A formal reference that lets a reader locate the source of a quote.
A citation that points to the exact page, paragraph, or section where a quoted or paraphrased passage appears.
A note printed at the bottom of a page giving a citation, a qualification, or a small side-comment.