GUI Design : Affordance

the perceived and actual fundamental properties of the object that determine how it could be used

appearance indicates how the object should be used

• chair for sitting
• table for placing things on
• knobs for turning
• slots for inserting things into
• buttons for pushing

complex things may need explaining but simple things should not

	Needs familiar idiom and metaphor to work: sliders for sliding, dials for turning what does some of the buttons do? is the musical notes a button?
	visual affordances for basic window controls are absent. what does the button to left of the slider do? what is the purpose of the phone handle...just a graphic?
	Handles on left and right indicate for lifting device....but, these are meant for scrolling.