The following definitions of the symbol/index/icon triad are interpreted from Charles Sanders Pierce’s analysis and Merriam-Webster’s dictionary.
Symbol: Something that stands for something else. A symbol has a convention-based relationship with object it signifies [alphanumeric symbols]
Index: Something that leads to one particular fact or conclusion. An index is directly influenced by an object [weathervane, thermometer]
-Can be further broken down into tracks [pawprints], symptoms [fever], or designations [pointed finger]
Icon: A pictorial representation. An icon has specific properties in common with objects [portraits, diagrams]
-Can be further broken down into image, metaphor [representing a parallelism in something else] and diagram [subway map is a diagram of the actual subway]
More words I’m compelled to define before I have one more conversation about my thesis.
Convention: A usage or custom especially in social matters; a rule of conduct or behavior; an established technique, practice or device.
Semiotics: A general philosophical theory of signs and symbols that deals with their function in both artificially constructed and natural languages.
-Comprises syntactics, semantics, and pragmatics
–Syntactics: Formal relations between signs or expressions in abstraction from their signification and their interpreters. Syntax is concerned with structure in a sentence.
–Semantics: The study of meanings. Semantics is concerned with meaning to a sentence.
-connotative: to imply [usually more emotional associations]
-denotative: to indicate [usually to describe in a more literal way]
–Pragmatics: The relation between signs or linguistic expressions and their users and the environment in which they occur.
Legibility: Refers to how easily one letter can be distinguished from another.
Readability: Refers to the relative ease with which a typeface can be read when characters are laid out in works, sentences, and paragraphs. [thank you Edvin Yegir – my thesis advisor – for clarifying that for me]
And more words I had to define after reading Jan van Toorn’s essay “A Passion for the Real”.
Dialectic: The discussion and reasoning by dialogue as a method of intellectual investigation.
Dialogic: Of, relating to or characterized by dialogue.
Didactic: Designed or intended to teach.
Polemic: An agressive attack on the opinions of another; an aggressive controversialist.
Polyphonic: Relating to a style of musical composition employing two or more simultaneous but relatively independent melodic lines.
Side note: While I was working on this I was reminded of a project my friend Betsy did. She took the actual pages of the dictionary and removed all unnecessary content with a black marker from the definitions she needed. When I was looking these words up I realized how much superfluous language there is in dictionary definitions, and you have to really dig and reinterpret in order to make sense of it all.