If you’ve worked in or studied UI design – or, if you’re a bit longer in the tooth like me, Human Computer Interaction – ‘Affordance’ is a term that you’re probably quite familiar with. Wikipedia gives the basic definition as :
An affordance is a quality of an object, or an environment, which allows an individual to perform an action. For example, a knob affords twisting, and perhaps pushing, while a cord affords pulling.
If you’ve done the HCI/UI thang though, what you’re probably more familiar with perceived affordance as defined by Don Norman in The Design Of Everyday Things, which is a much more context dependent kind of a concept.
I've tried to cover a full range of topics as an introduction to iOS design.
Lots covered, and links to even more in depth coverage of a whole load of important iOS design background. Great stuff and a must read.
Contemporary mobile voicemail is an amazing technology. Even the humble answer-phone tech from which it evolved is pretty damn clever, not just technically, but conceptually. The essence of the concept, and the thing that makes it so great, is that simply by swapping a synchronous communication for an asynchronous one it offers the opportunity for turning a failed effort at communication into a fulfilled one.
For an added bonus, the asynchrony also offers productivity benefits : the caller knows their message has been delivered and will be received and can move on to the next task. The callee, safe in the knowledge that communication has been received and stored while they were unable – or unwilling – to engage in a synchronous communication can pick up the message later and prioritise and schedule a response.
And that’s just the model with the answer phone. Throw in modern mobile communications networks and it just gets better. The computer at the phone company will not only patiently store the message, it will then diligently hunt me down wherever I happen to be in the world and make sure I’m notified that there is a message waiting.
There is literally no way for me to miss a message. Unless, of course, the caller doesn’t leave one. Which, of course, happens around 99% of the time…
Over at scripting.com, Dave Winer discusses RSS readers with Brent Simmons.
I can scroll back to the point where I hit something I seen. Quickly. My memory is perfectly capable of telling me I've seen something before. You can rely on it, people can do this.
No. No you can't. This is UI design 101, lesson 1. I mean that literally. This was in the first lecture of the first year class on Human Computer Interaction I took in the hazy days of uni. The more cognitive load you place on your user, the worse their experience of your interface is going be, and the approximate memory span of the average human has been extensively studied since the cognitive psychologist George A. Miller published his landmark paper The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information in 1956, which you will find cited in the first chapter of any HCI book you pick up,
There may well be specific subsets of users for whom this is not an issue, but the general case is the exact opposite.