In Saussurean semiotics, a sign is named as the relationship between the signifier and the signified. The signified is not the actual thing in the external world, but rather the concept of that thing. This is a subtle but important point. American philosopher Susanne Langer explains:
Symbols are not proxy for their objects, but are vehicles for the conception of objects.... In talking about things we have conceptions of them, not the things themselves; and it is the conceptions, not the things, that symbols directly “mean”.1
So, the word apple cannot itself be eaten, nor can the concept of apple. But the word provides us with a way of identifying the concept of the thing we can eat. The word apple signifies a concept that we both understand, and it is in the relationship between the word and the concept that I am able to speak to you about it without having to actually hand you an apple.
The concept, like the thing, exists outside of the signifier, the word apple. And it's interesting to note that the referent (a physical apple) does not need to be part of this at all; certain concepts have no material existence. Freedom can only be understood within the dyad of signified and signifier; freedom does not exist as a thing we can hold in our hands. So in our understanding of a sign then, the material referent is only consequential in that a concept without a referent is perhaps less "real" to us. We understand the concept of freedom by convention, but we cannot experience it in the same way as we can an apple.
It is through the utility of this relationship between signified and signifier that we are able to communicate with one another. But this structure also sets up an interesting thought: if your experience of an apple has been colored in any way by the word apple, then isn't your experience of reality dependent on the systems you use to interface with it? As an example, consider the effect of having different words in different languages. In France, you eat a pomme, not an apple. The quality of the word pomme, its soft roundness, can be seen to influence one's relationship with the concept of apple. And the experience of eating an apple has suddenly shifted: it's not hard to imagine that a pomme tastes just a little different than an apple. If a chick says pío pío to a Costa Rican, but cheep cheep to an American then the perception of that reality is inherently different to the two.
So the mode of a sign can influence the very nature of reality for someone experiencing it. To this point we've used language as an example to help us investigate the nature of signs, but the sign's mode can take any shape. It does not matter whether the signifier is a word, a piece of music, a light (think: stoplight or lightning flash), or an icon; each interface itself imparts character to the experience of it. A stop sign could have been green rather than red, which would change the connotations of the colors (red might no longer suggest danger, for example) and would certainly change your experience of the color. The referent would remain the same (i.e. the command to stop), but our perception of the world would be different.
In the world of UX, this has a weighty consequence. First it shows how a user's experience of a digital interface is connected with a user's conception of reality. This is particularly interesting because UI has moved beyond being a proxy for a physical referent. Even graphical UI elements that grow out of a physical counterpart (like radio buttons or tabs) are an abstraction of an abstraction. A radio button originally helped control preset stations on a car radio. But that itself is giving physical form to a non-physical demand (not to mention the move from analog to digital). One might posit that with each layer of abstraction, the “realness” of a meaning becomes less obvious; what is most real about this reality is the experience of it.
The suggestion here is that the user experiences we design are perhaps more fundamentally provoking than we might suppose. A user interface is no longer just a design, but a new intersection connecting a user to their reality. As such, we should consider the possibility that the same fundamental needs (see Maslow's hierarchy of needs) we look for in our conventional reality should be addressed in UX. Ideas like safety and comfort, confidence and respect, and self empowerment would seem prima facie to improve user experience. But here we see evidence implying that these needs should be a salient focus to our work. If this conclusion is true, then we must consider ourselves stewards of our users on an ontological level.
A person's experience of reality is colored by the interface to that reality. This interface might be anything from language to music to a web-based user interface. This suggests that the responsibility of a UX designer begins with establishing comfort at the level of essential human needs.
1 Langer, Susanne K. Philosophy in a New Key: A Study in the Symbolism of Reason, Rite, and Art. 3rd ed. Cambridge: Harvard UP, 1957. 60-61. Print.