A type of sign in which the iconic function is the dominant sign function, but also the symbolic and index functions are clearly present.
If a coach sketches a diagram of the match on the blackboard, he constructs a sign that in some important aspect resembles his object, which means that the sign is iconic.
But the chart also relies on conventions and indices.
There is a convention to denote by X the player from one team and O – the player from the other team. In addition, the X’s and the O’s have an index function. If the coach draws three Xs and says “Shikula, it’s you, Alan, it’s you; and Vinnie is you; that’s where the ball should go,” the signs already have index function.
Charles S. Peirce pays attention to diagrams, noting that they combine iconic, symbolic, and indexical functions.
“A chart is” in his words “a representamen that is most iconic in its relationship and is intended to be one by convention. Indices are also used more or less in charts” (CP 4.418).
