Barthes' very compact summary, of what he thinks as the key elements of semiology, is often considered as one of the fundamental writings about semiotic theory. In this equally compact article, I try to summarise how it can be relevant for the research of interface icons.
In semiology there is always a connection to language, even when studying systems of images. This is equally true about interface icons. As we look at an interface icon, we almost compulsively think of the word that it can be translated to. According to Barthes, semiology is a part of linguistics. This is contrary to Ferdinand de Saussure, who considered linguistics as a branch of semiology.
Language, and also the language of interface icons, is a social institution, a system of contractual values that resists modification of a single individual. It is like a game with its own rules, which can be only handled after a period of learning.
Speech and Language
Historically, speech comes before language. Speech gives birth to language. Language is at the same time a product and instrument of speech. In practise, the theory of designing icons could be considered a language, and the way they are utilized in everyday interfaces is equivalent to speech. Speech in such form has very little variation compared to speech in real life.
Barthes explores the relationship of speech and language in a semiotic system, by examining systems of clothing and fashion (the garment system), food, automotive and furniture. The language of these systems is defined by a smaller deciding or manufacturing group, where as the speech consists of the ways in which the large masses utilize the products. For instance, in the garment system, language could be the generally accepted rules of associating different types of clothing. Whereas, speech could be the way that clothes are worn, and how individual people combine different pieces of clothing. In the icon system the volume of speech, or free association, is small.
Following the Saussurean terminology, Barthes points out that the signifier and the signified are components of a sign. The same goes for icons. An image of a trash can is not an icon by itself, it is only a metaphorical logical icon when it is connected to the intended action of deleting files. He also mentions that Saussure chose the term sign rather then symbol since in his opinnion symbol implied motivation.
Arbitrary or Unmotivated
In describing the relationship between the signifier and the signified, Saussure used the term arbitrary. In linguistics another closely related term is unmotivated. These two terms describe two different levels of logical relation. A system is arbitrary when its signs are founded not by convention, but by unilateral decision. A sign is motivated when when the relation between its signified and signifier is analogical. According to this logic, it is possible to have systems which are arbitrary and motivated, and others which are non-arbitrary and unmotivated. To put it in layman's terms, if a designer decided to use an image of a bloodhound to signify the search function, the relation would be arbitrary and motivated.
It is not enough to study the way in which an individual sign works. It is equally important to consider the context, or the value a sign has in relation to its neighbours. A single chain: signifier->signification->signified, is not enough. One also needs to consider the surrounding system. The syntagm is a space of combination of signs. In language it is a linear and irreversible chain, where one word follows another. In addition to the syntagmic plane there exists a second plane of relationships between signs, which is the associative or systematic plane. It is a set of varieties of a single element. For instance in an architecture system this would entail the variations in style of a single element of a building.
The Classification of Oppositions
Barthes introduces Cantineau's principle of distinctive opposition in the language, which he attempts to apply to semiological oppositions. A principle of classification is possible by examining the similar and dissimilar element of the opposition. These oppositions can be bilateral or multilateral. In bilateral oppositions the common element of two terms is not found in any other oppositions of the code. As a simple example of the latin alphabet the opposition of the letters E and F is bilateral, because the common shape F does not exist in any other letter of the alphabet. In multilateral oppositions the common element exist in more than two terms. In the alphabet example, this opposition can be found in the letters P, B and R, where the common shape in all three is P. This classification of oppositions is similarly applicable to classification of interface icons.
Barthes, R. (1977). Elements of Semiology. New York. Hill and Wang.