Practical ProgrammingCOMP153-08S

Week 5 L2: HCI

What is HCI?

• Human Computer Interaction

1. the study of humans

2. the study of computer technology

3. the study of how they influence each other

• Designing systems that are more usable

Usability

• Does what user wants in the way they can easily understand.

•Microsoft Entourage– has a calendar/diary– you can have reminders that events

are about to happen (eg meetings)– reminders appear in a popup

window– but they don’t appear on top of all

other windows– so you might never see them!

Poor Usability is seen in software

Apple puck mouse

– for a while was the standard mouse provided with Apple computers

– too small to fit into hand comfortably

– it’s round, so difficult to tell which way it is pointing

– people had to buy add-on covers to make it usable

Poor Usability is seen in hardware

Some Key Usability Concepts

1. Visibility

The control panel at the 5 mile Island Nuclear Power Plant. The controls were so badly designed that the user had to modify them.

Some Key Usability Concepts

2. Affordance

Te Taka’scrock

pot

Some Key Usability Concepts

2. Affordance

Some Key Usability Concepts

3. Mappings

Some Key Usability Concepts

4. Feedback

Red Blue Green Yellow White

US danger masculinity safety cowardice purity

France aristocracy freedom, peace

criminality temporary neutrality

Egypt death virtue, faith, truth

fertility strength

happiness, prosperity

joy

India life, creativity

prosperity, fertility

success death, purity

Japan anger,

danger

villainy future, youth

grace, nobility

death

China happiness heavenly Ming & others

birth, wealth,

death, purity

Some Key Usability Concepts

5. Understanding Users

Designing for Usability

1. Understand user needs– Study them – what really happens in the world?– Involve them

2. Prototyping– Early on build versions of the system that the user

can see and use

– Get comments

– Listen and adjust

3. Use design guidelines– Learn from others– Rules of good practice

So….

• Paper sketches– Show user, modify

• .net forms– Just layout– Some functionality– Again, show users, modify

Design guidelines

• Through experience and experiments, lots of good design advice available.

• You’ve seen a range in the Zak book:– Tooltips (why?)– Access keys (why?); choice of letter?– “If an operation is destructive, prompt the user to verify

that he or she wants to proceed with the operation” – Appendix B GUI Design Rules

• No easy, magic way for good design though. Guidelines are just guides…

Taking things further

• Read– “The psychology of everyday things” Don Norman.– Look at www.baddesigns.com (site about how bad

design makes life difficult)– Look at www.useit.com (site about usability)

• Practice good practice– Prototype your vb apps – sketch, show users,

redesign– Apply good design guidelines

• Do COMP258 (Engineering Usable Systems)

THE END

of the lecture