Human Interface Design

Learning Outcome

The aim of this activity is to raise awareness of human interface design issues. 

Because we live in a world where poor design is rife, we have become accustomed (resigned?) to putting up with problems caused by the artifacts we interact with, blaming ourselves (“human error,” “inadequate training,” “it’s too complicated for me”) instead of attributing the problems to flawed design. 

The issue is greatly heightened by computers because they have no obvious purpose—indeed, they are completely general purpose—and their appearance gives no clues about what they are for nor how to operate them. 

Problem 1

The first problem the Oompa-Loompas face is getting through the doors carrying steaming buckets of liquid chocolate.

They cannot remember whether to push or pull the doors to open them, or slide them to one side.

Consequently they end up banging into each other and spilling sticky chocolate all over the place.

Affordances: Chair, Table handle what about a PC?

Doors are very simple objects. Complex things may need explaining, but simple things should not. When simple objects need pictures, labels, or instructions, then design has failed


Problem 2

The pots containing different kinds of chocolate have to cook at different temperatures. In the old chocolate factory the stoves were as shown below.  The Oompa-Loompas were always making mistakes, cooking the chocolate at the wrong temperature, and burning their sleeves when reaching across the elements to adjust the controls.

Natural mapping: Physical Analogies

They are easily learned and always remembered.

Problem 3

The factory is full of conveyor belts carrying pots of half-made chocolate in various stages of completion. These conveyor belts are controlled manually by Oompa-Loompas, on instructions from a central control room. 

The people in the control room need to be able to tell the Oompa-Loompa to stop the conveyor belt, or slow it down, or start it up again. In the old factory this was done with a voice system: the control room person’s voice came out of a loudspeaker by the conveyor belt controls. But the factory was noisy and it was hard to hear.

Develop a Traffic light system?

Transfer effects—people transfer their learning and expectations of previous objects into new but similar situations

Problem 4

When one shift of Oompa-Loompas finishes work in the chocolate factory, they must clean up and put away pots and pans and jugs and spoons and stirrers ready for the next shift. 

There is a cupboard with shelves for them to put articles on, but the next shift always has trouble finding where things have been put away. Oompa-Loompas are very bad at remembering things and have trouble with rules like “always put the pots on the middle shelf,” “put the jugs to the left.” 

Visible constraints - make it obvious where everything is supposed to go.

Problem 5

In the main control room of the chocolate factory there are a lot of buttons and levers and switches that operate the individual machines. 

These need to be labeled, but because the Oompa-Loompas can’t read, the labels have to be pictorial—iconic—rather than linguistic.