icon

An icon is a sign that represents its object by resemblance. The representamen shares some quality or structural feature with the thing it stands for — a portrait resembles the person depicted, a map resembles the territory, a diagram resembles the structure it represents.

Peirce distinguished three subtypes of icon [@peirce_CollectedPapers_1931]:

• Image: resembles the object in simple qualities (a photograph, an onomatopoeia)
• Diagram: resembles the object in relational structure (a flowchart, a mathematical graph)
• Metaphor: represents one thing by its resemblance to another in some respect

Iconic signs are never purely iconic — a map uses conventional markings (symbols) and is produced through a causal process (indexical). The classification identifies which aspect of the sign relation predominates, not which is exclusively present [@chandler_Semiotics_2007].

Related terms

• index — a sign connected to its object by causal or spatial relation
• symbol — a sign connected to its object by convention
• sign — the triadic relation in which icon is one type

Source: Peirce, Charles Sanders. Collected Papers. Harvard University Press, 1931–1958.