Monday, 16 September 2013

Affordance: the case of door closing

Last week, I was at (yet another) hotel. In the Ladies' (and presumably also the Gents'), the doors had door-plates on the inside, which facilitated pushing but not pulling. Within HCI, this is often referred to as the object affording a particular action. See, for example, work by Gaver and Hartson. In fact this example goes further than affording: it determines what is physically possible. In the case of doors, the assumption is that on one side you expect to pull and on the other you expect to push.

The problem was that in this case the door hinge was very simple: the door did not automatically close. So the only way to close the cubicle door was to pull on the small handle that was designed as a lock (that afforded turning but not pulling). The assumption behind having a plate on one side and a handle on the other is that there is a default position for the door, which could have been achieved if the "system" (aka the hinge) was set up to automatically close the door. But it didn't. In this case, the user has to both pull and push the door to get it to the desired positions -- and yes, privacy is valued by most of us in this situation, so most do want to be able to close the door as well as open it!

I've previously commented that we seem to be unable to design interactive devices as simple as taps; it seems that this extends even to doors... and I don't think interactions get much simpler than this.

Friday, 6 September 2013

The look of the thing matters

Today, I was at a meeting. One of the speakers suggested that the details of the way information is displayed in an information visualisation doesn't matter. I beg to differ.

The food at lunchtime was partly finger-food and partly fork-food. Inevitably, I was talking with someone whilst serving myself, but my attention was drawn to the buffet when a simple expectation was violated. The forks looked like this: I expected them to be weighty and solid. But the one I picked up felt like this:

– i.e., insubstantial and plastic. The metallic look and the form gave an appearance that didn't match reality.

I remember a similar feeling of being slightly cheated when I first received a circular letter (from a charity) where the address was printed directly onto the envelope using a handwriting-like font and with a "proper" stamp (queen's head and all that). Even though I didn't recognise the handwriting, I immediately expected a personal letter inside – maybe an invitation to a wedding or a party. But no: an invitation to make a donation to the charity. That's not exciting.

The visual appearance of such objects introduces a dissonance between expectation and fact, forcing us to shift from type 1 (fast, intuitive) thinking to type 2 (slow, deliberate) thinking. As the fork example shows, it's possible to create this kind of dissonance in the natural (non-digital) world. But it's much, much easier in the digital world to deliberately or accidentally create false expectations. I'm sure I'm not the only person to feel cheated when this happens.