Fei Shu, Kaijie Jia
Citations are a central mechanism of scholarly communication and a foundational element of bibliometric indicators used in research evaluation, yet their meaning and function remain theoretically contested and empirically complex. This literature review synthesizes foundational and contemporary scholarship on citation practices by examining their historical development, conceptual definitions, functional motivations, empirical investigations, and theoretical foundations. Drawing on both author-centred studies (such as surveys and interviews) and text-centered approaches (including citation context and classification analyses), the review shows that citations serve multiple, overlapping functions, ranging from acknowledging intellectual influence and providing background or methodological reference to persuading audiences, positioning research within disciplinary traditions, and negotiating scientific credibility. The review traces the development of citation theories from normative perspectives rooted in Mertonian sociology of science—which view citations as formal acknowledgements and instruments of reward—to constructivist approaches that emphasize their rhetorical, strategic, and socially situated character. Empirical evidence across disciplines consistently demonstrates that citation behavior cannot be reduced to a single motivation or interpreted as a uniform signal of research quality or influence; instead, it reflects heterogeneous practices shaped by disciplinary norms, social dynamics, institutional incentives, and author judgments. By organizing a diverse body of literature into a coherent analytical framework, this review highlights enduring tensions between competing theories while also examining integrative approaches that seek to reconcile them. The findings underscore significant implications for bibliometrics and research assessment, particularly the limit of raw citation counts and the need for more contextualized and responsible uses of citation indicators.