As designers it is often our responsibility to imagine the future possibilities of things. We rarely get to design independent of social and cultural contexts, and we never get to design independent of the perceptual capabilities of our users. You could design a marvelous interface that makes terrific use of “color” outside of the visible spectrum, but it is unlikely that a human would be able to see it. It would be rare indeed to find a visual designer who bemoans the shackles of human perception, which unfairly force her to work entirely within the visible light spectrum.
Recently, Adam Greenfield took Apple to task regarding the design of some of their iOS apps, including iBooks, Compass, Calendar and Notes. His criticism is that these applications are too skeuomorphic; that they feature visual cues from their real-world analogues that insult the future-facing potential of this new generation of touch screen mobile devices:
The iPhone and iPad, as I argued on the launch of the original in 2007, are history’s first full-fledged everyware devices — post-PC interface devices of enormous power and grace — and here somebody in Apple’s UX shop has saddled them with the most awful and mawkish and flat-out tacky visual cues. You can credibly accuse Cupertino of any number of sins over the course of the last thirty years, but tackiness has not ordinarily numbered among them.
Every interface exists within a cultural and perceptual context. Even on touch screen devices, controls are often rendered in a manner that reflects analogues in the physical world. The metaphorical basis of these real-world analogues can be as culturally literal as the bookshelf view in iBooks, or as perceptually abstract as the use of a gradient and drop shadow to communicate three-dimensionality.
The whole concept of affordance depends on there being a coherence between the function of a particular interaction, and the manner in which it is represented visually. If there isn’t enough coherence between an interactive element and the function it performs, the interface will likely be confusing, ambiguous and frustrating. Designers must decide which metaphors to leverage in the design of their interfaces, within the context of existing interactive patterns and real-world experience.
Just as a visual designer must work within the “constraints” of human visual perception, interaction designers must work within the constraints of analogous real-world experiences, existing interaction patterns, and cultural knowledge. These are welcome constraints, however, as they provide a wealth of meaning that can be effectively leveraged by an otherwise new interactive model.
Consider this. Is this button sticking out, or is it pressed in?
How about this one?
Technically, there is nothing about either of these images that objectively designates one as concave or the other as convex. However, in the physical world we are used to seeing objects lit from the top rather than from the bottom. As a result we perceive depth in images as though they too are lit from the top.
This may seem obvious, but it illustrates a very important point: on-screen images have meaning only insofar as we have something to associate them with. We are a ways off yet where our every interaction with the world is mediated by a screen, and so the physical world and its properties of light and shadow hold a trove of meaning that we can leverage as designers to communicate a sense of three-dimensionality. Even in the simple world of gradients, bevels and drop shadows, we are leveraging a metaphorical language steeped in our experience with the physical world.
Existing Interactive Patterns
Real-world experiences play a large role in mediating our perception of interfaces, but established patterns for interaction are also incredibly influential. Blue underlined text has no off-screen analogue, but through repetition and familiarization it has become widely recognized as representing a hyperlink. These patterns take time to become established, but when they do they act as a source of meaning that can be leveraged in our interactions.
Interactive patterns are certainly not limited to visual treatment, and with careful intent can quickly establish themselves. If we trace the evolution of Apple’s two-finger trackpad scrolling, to their multi-touch trackpads, to their multi-touch screens, it is clear they are deliberately training us in a new physical vocabulary. As this gestural language becomes familiar it becomes a resource for design, in turn clearing the way for more sophisticated gestures in the future.
Cultural knowledge and society comprise a final constraint within which we design interactions. Certain artifacts, materials and textures hold cultural significance, which we can leverage in our interfaces to communicate their intended use, or set the stage for a particular experience. A few apps and utilities in iOS, including Calendar, Compass, iBooks, and the ghastly Notes, come under harsh fire from Greenfield for their insultingly literal remediation of cultural ephemera. Compass looks like a brass compass! Your iBooks rest on your wooden iBookshelf! Notes looks like a yellow legal pad! Get it? NOTES?! Like the ones you WRITE?!?!
Now, I agree with Greenfield that the patronizing appearance of these applications is inexcusable, that the literal representation of their real-world analogues demonstrates a surprising lack of elegance and ambition on the part of Apple. However, I disagree with Greenfield on the assertion that cultural metaphors have no place in a future-facing mobile context.
I agree that Notes is an abomination, but it is not an abomination because it leverages cultural meanings, or because it attempts to channel a physical analogue in its form. It is a poor interface because it is a clumsy and inelegant implementation that takes the metaphor of a notepad far too literally. A better effort would be to distill the idea of a “note” to its absolute essence, and to extend it with the unique capabilities afforded by a mobile touch screen device.
The tackiness of these apps is clumsy and insulting, but to claim that screen-based interfaces should exist outside of physical experience, outside of cultural meaning, is nonsense. Real-world analogues are a useful metaphor for structuring the way we think about a possible design, as well as a resource to leverage in shaping how users think about our design. This doesn’t excuse the ham-fisted design of Notes, but it lends some context as to why it fails, and how it could succeed without completely dispensing with metaphor and physicality.