SIGNS

A SIGN is any form which conveys a meaning.  There are two ways to classify signs:

1. Signs may be classified according to whether they physically resemble what they signify.

            An ICON is a sign which physically resembles what it represents.  A map is an icon of the geographic locality it represents.  A picture of rocks falling is an icon of a rock slide. Also, icons show different degrees of iconicity, or natural resemblance to what they signify.  For instance, some pictures are very exact representations (an example would be a photograph, which is an icon of what it represents); other pictures may be more abstract (such as the conventionalized shapes of a man and a woman on bathroom doors).  Nevertheless, if the physical resemblance is detectable, then the picture could be called an icon.

            Sound symbols can be iconic, too. When telling a story, for example, a narrator may make a whistling sound to signify wind; this whistle is an icon for wind.  A very small number of words are also iconic to varying degrees, examples being words such as "tick", "thud", or "oink". Iconic words are known by the Greek term onomatopoeia.  In every instance, to at least a recognizable degree, an icon actually looks or sounds like what it represents.

            A SYMBOL, on the other hand, is a sign which bears no readily recognizable physical resemblance to what it signifies. Most words in any language are symbols. For instance, the word apple neither looks nor sounds like an apple (how would an apple sound, anyway?).  The relation between the word-symbol "apple" and the fruit it signifies is arbitrary, established by a convention handed down by word of mouth in a given speech community.  For this reason, this fruit is signified by completely different sounds in other languages. In Mandarin Chinese it would be "ping guo"; in Cherokee "sunta";  in Spanish "manzana".

            And there are plenty of other symbols besides words. Many graphic signs also show an arbitrary, conventional relationship to their meaning.  For instance, the octagonal shape of a stop sign is a symbol, as is the white and red striped pole which signifies a barber shop.  The shape of most numerical digits is arbitrary: 2, 3, 4, 5, 6, etc. (although one could argue that the shape of the digit 1 is somewhat iconic).

2. Signs (icons and symbols) can also be classified according to how they are used.  They may be used to point directly to what they signify, such as a barber pole (a symbol) or a rock slide sign (an icon). A sign which is used in direct temporal and spatial connection to what it signifies is said to be used as an INDEX.  The same sign used without such a direct connection, such as a stolen stop sign leaning against the wall of a garage, is a NON-INDEX.  The whistling sound of wind is an index of real wind, but a storyteller's imitation is a non-index used to conjure up the image of wind in a setting where there is no real wind.  The stylized icons of a man an a woman are used as an index of the presence of a man's or woman's bathroom, but a painting of Mona Lisa (also an icon) is a non-index, since you won't find the real Mona Lisa nearby.  Words may be used either as an index or a non-index. For instance, the word apple may be uttered to indicate the presence of a real apple (word used as index) or simply to mention the concept apple in the complete absence of any real apple.  This is part of what gives human language its great versatility in contrast to animal communication, where signs must be used as indexes in all circumstances).  

**THINK UP MORE EXAMPLES OF ICONS, SYMBOLS AND INDEXES