Deliberate Actions

Oftentimes, I see friends and family who aren't particularly tech-savvy struggle to navigate a user interface. Moreover, even when no action is being submitted, they still seem overly cautious of their input. The truth is: they lack confidence.

A fair conclusion is that their lack of experience is to blame. They haven't yet built a solid conceptual model to recognise what seem like very common conventions to me. But at the same time, I believe that this might just be a sad excuse for bad design. A product made for humans shouldn't just build on top of intuition—it should help develop it. Good design should not only rely on prior exposure to work. A restaurant that expects every new customer to already know their concept would be failing at service.

Over the years, I've built a sense of taste and an intuition of what feels right. But I recognise that might not be enough. I've proudly shown my interfaces to people around me, and while they're sometimes impressed (I don't think the majority cares about this kind of stuff), my non-tech-savvy friends and family sometimes still need instructions. That led me to wonder: is there more of a science behind this that I could explore?

An affordance, a term coined by psychologist James Gibson and later adapted to design by Don Norman, is a relationship based solely on the qualities of the object and the user's capabilities—whether it is visible to the user or not doesn't matter. In our context: a mouse may afford clicking, a screen may afford tapping or swiping, and a keyboard may afford typing.

In contrast, a graphical interface made up of pixels does not possess the qualities of a physical affordance. A blue underlined word on the screen may appear clickable, but in reality, it is the mouse that affords clicking—and it maintains its affordance regardless of what the user is hovering. However, clicking when the cursor hovers this particular word may give the user the ability to navigate—a quality not provided by its surrounding, dark gray words. The point being that this could only be discovered by its contrasting appearance: being blue and underlined, which gives it its perceived affordance of being clickable.

Such properties are what Norman calls signifiers, and they indicate to the user where certain actions can take place. Signifiers enable the formation of perceived affordances and may be either explicit or implicit. But the effectiveness of implicit signifiers depends on the user's current conceptual model and their past experiences. According to Jakob's Law, users prefer your interface to work the same way as all other interfaces they already know. Leveraging existing conceptual models allows for fast and cheap improvements of user interfaces.

The following example in figure 3 explores a video editor's timeline interface. In this case, the handles act as implicit signifiers, indicating the affordance of dragging the start and end points across the 60-second timeline. The shape of these implicit signifiers leverage existing conceptual models popularized by Apple. Similarly, the cursor changing its shape over different parts of the fragment also acts as a signifier, indicating the presence of another affordance: dragability.

Affordances are pointless if they are not visible to the users. So, the responsibility of the designer is to ensure that the relevant, desired actions are perceivable.

Once the user understands the actions provided by the interface, we need to ensure that these actions can be performed smoothly and confidently. Besides giving a button its perceived affordance of being pressable, it should be easy to click or tap, and depending on its consequence, consider accidental activation.

Ergonomic design is the application of psychological and physiological principles to the design of products or systems. Its primary goals are to decrease human error and to increase productivity and comfort. Ergonomics in the context of interaction design can be divided into two fields: physical ergonomics and cognitive ergonomics.

Fitts' Law supports physical ergonomics, and states that the time it takes to move a pointer, like a mouse or finger, to a target depends on the distance and size of that target. Similarly, the Steering Law states that the longer or narrower a path is, the slower a user will need to move through it. For cognitive ergonomics, Hick's law states that the time it takes to make a decision increases with the number and complexity of choices.

Accessibility is an essential component of good ergonomic design and in favour of accessibility, a digital interface should be operable to people with physical, cognitive or sensory impairments, with keyboard-only navigation and screen readers. Ideally, affordances of an interface should be as analogous to all users as possible.

To be continued, thanks for being an early reader! ❣️