Flat design, a major trend in user interfaces, basically consists of discarding any visual excess of the interface components, either widgets or icons. We may take it as a sort of going back to the swiss graphic style from last century applied to the case of user interfaces. Flat design utilizes lines and shapes as visual units, diminishes the use of texture and shadows, and employs color to cue. Moreover, shapes change form and color through time in order to indicate the current state of the system. One interesting aspect that we can notice about this type of interface is the recurrent use of circular forms. When circles and circumferences—either complete or fragmented—are employed to compose interface widgets, they seem to express time effectively without the necessity of more visual information.
For instance, to indicate the progress of saving changes, WordPress incorporates a circular indicator composed of two circles. The big one is filled with a gray color, whereas the small one is filled with the same color as the background—a lighter gray. Rotating in a clockwise fashion, the small circle indicates that saving is still ongoing.
Whatsapp, the instant messaging app, employs a circular widget to indicate the delivery status of a video. This widget is composed of a circle with a shape within. At the beginning the circle is presented with a transparent dark gray that changes to a transparent white once the video is delivered. In the meanwhile, the line that circumscribes the circle is displayed progressively to indicate the current status. In turn, the inner shape indicates the available action. First, it has the form of a square to indicate the capability of interrupting the process. Once the video is delivered, it transforms into a triangle, the universal icon for play. An interesting feature regarding this widget is the double communicative function achieved with its design. On one hand, it shows the progress of delivering the video. On the other, it communicates its affordance as a button.
When there’s no video input in a Google hangout, as occurs when it’s used to make phone calls, the interface displays a big circle with the phone number, the duration of the current call, and the cost per minute. Below, two other circles are collocated—as buttons—to dial a number or hang up, respectively. When a person on the other end speaks, the big circle modifies the thickness of its circumference in a wavy fashion according to the intensity of the voice. By means of this visual cue, the user sees when the other person speaks and the intensity of the voice.
The sketching app for iPad named Paper introduces a undo functionality consisting of collocating two fingers over the screen and rotating them in a counter clockwise manner. They call it rewind. Before the user starts rewinding her actions, the widget displays a full circle in dark gray. As the user rotates her fingers, the filling decreases counter clockwise. There are two interesting aspects regarding this widget. First, the way the undo function is interpreted by gestures—since we are accustomed either to employ a menu or to press the keys CTRL + Z. The second aspect is that a user can perceive the amount of work she has put on the sketch so far. That is, the circle’s filling decreases in proportion to the number of actions carried out by the user.
In addition to the functional aspects observed above, we can notice several examples where the circle is more related with aesthetic value. It’s employed to compose buttons, to indicate scales, or even to clip images—as in some profile pictures. There’s no functional value added in these cases. The circle takes the place of rectangular shapes employed in the past.
Notwithstanding, this approach implies a compromise regarding the communicative aspect of the interface. For instance, in iOS 7, the increasing bars originally employed in the widget to display the strength of the signal have been substituted by row of circles. By comparing the differences of size among the original bars, the user could (visually) read the widget in terms of physical magnitude. The different sizes contributed to the metaphorical construction in the user’s mind. By observing the smallest bar, the user could depict the weak presence of waves in the air. Conversely in the case of the biggest bar, the user may depict the environment flooded of invisible waves. This is not the case of the row. The circles are not associated to any physical magnitude—they’re the same diameter. The user only evaluates the strength of signal according to the number of filled circles. Thus, the circles are perceived as units of a scale; a part of a whole. Consequently, the user faces a more abstract understanding of the concept of the strength of the signal. That’s the core of flat design in user interfaces: increasing the level of abstraction and breaking with the strong metaphorical association with the real world.
Circle-based widgets produce effective results because they encapsulate affordance and time. When the circle is employed as a unit of composition, its basic quality to represent a whole allows the user not only to comprehend the current status of the system, but also to infer future outcomes. For instance, a whatsapp user will know that something went wrong when sending a video if the circumference never completes. On the other hand, a circle also corresponds to a reliable bi-dimensional mapping of any spheroid objects we’ve been interacting with since we were born (e.g. knobs). Because of the latter, a user may easily know how to interact with circle-based widgets in an interface. Although the circle-based widget cannot escape from its metaphorical nature, it certainly entails a more abstract visual representation; perhaps, more easy to dissociate from its origins in the real world.
The aforementioned matters regarding the effectiveness of the circle in flat design correspond to a situation of shaping and composing a visual/multimedia usable message, in other words, of information design. Moreover, the ongoing consolidation of ubiquitous computing, gesture-operated interfaces, and the forthcoming incursion of flexible displays represent a challenge for information designers. Although the visual principles and design principles will practically remain the same, the signifiers attributed to interacting with technology will depend on the context of use. Different types and levels of literacy, sociocultural and socioeconomic factors, the development of technology, among other circumstances, will foster the reinterpretation of ways to visually code information. Since proper information design underpins a pleasant user experience, taking care of visual coding is a matter that goes beyond aesthetics or fashion. Information design as shaping the content is not enough. Information design participates in shaping the context as well.