Behaviour
Affordances & Controls
Affordances and controls are simply terms for the buttons, knobs, sliders, dials, handles, switches, joysticks, levers, wheels - to name a few - that we use to operate manmade things. Until very recently, all of these controls were mechanical and you could tell how they worked by simply looking at them. Digital controls have evolved from mechanical ones, and their functionality is based the symbolic, or metaphorical, use of objects we are already familiar with in the physical world.
Check out how Funnel Design uses metaphorical controls.
The term affordance was popularized by Donald Norman in his book The Psychology or Everyday Things.
What do you think he means by the following statement?
“I should have used the term 'perceived affordance,' for in design, we care much more about what the user perceives than what is actually true.” ~ Donald Norman
History of the Button is a quick walkthru of the evolution of the most common affordance in both the physical and the digital environment.
What exactly is a button?
Watch this video of Bill Verplank talking about the world of continuous control and the world of discreet control.
How does that relate to the interactions below?
Assignment
Take digital photos of switches, buttons, controllers etc. Create a web page of your photos cropped to a consistent size and embed them in the table format below. Analyze how these objects allow people to interact with the world (both real/physical and digital/virtual).
| REAL WORLD | WHAT? | HOW? | ACTION | WHY? | STATES or FEEDBACK | DIGITAL WORLD? |
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Dial | Turn clockwise | Choose | To select the spin cycle or mode for a washing machine. | Pointer on dial is pointing to active setting. Settings are labeled and marked with a thiick line. Pointer aligns with line. Settings are static - they don't change when selected.
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Handle | Push down | Open | To release the invisible mechanism that keeps the door in its closed position | When the handle is up, the door is closed. Pushing it down allows the User to pull the door open. When the door closes, the handle reverts to the closed state. |  |
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Knob | Twist | Lock | To engage or disengage the lock that prevents the door from being opened | When the knob is vertical the door is locked. When the knob is horizontal, the door is unlocked. |  |
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Slider | Slide up and down | Adjust | To control the amount of current going to the light fixture |
When the sliding dimmer controls are all the way up, the lighting level is at its brightest. Sliding the dimmer controls down gradually reduces the amount of brightness coming from the light fixture. |  |
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Switch | Flip up or down | On/Off | To enable current to flow or not flow to the light fixture | When the swith is in the off position (down) the light is off. When the switch is in the on position (up) the light is on. |  |