Usability A brief introduction Philip Morton http://www.flickr.com/photos/david_nicholai/987226801/

What is usability? Why is it important? How does bad usability come about? How can you improve it? Further reading Questions Outline

What is usability?

Why is it important?

How does bad usability come about?

How can you improve it?

Further reading

Questions

What is usability? Usability is two things: A measure of how easy user interfaces are to use. The methods for improving ease-of-use during the design process. Usability is two things: In other words, how people interact with the systems and objects around them.

A measure of how easy user interfaces are to use.

The methods for improving ease-of-use during the design process.

What is usability? Usability is all around us:

What is usability? Usability is all around us:

What is usability? Usability is all around us:

What is usability? Usability is all around us: http://www.flickr.com/photos/96854970@N00/3320024073

What is usability? Usability is all around us: http://www.flickr.com/photos/caddick/471212949

Learning : How easy is it for people to accomplish basic tasks the first time they encounter a system? Efficiency : Once people have learnt the design, how quickly can they perform tasks? Memory : When people return to the system after a period of not using it, how easily can they re-establish proficiency? Errors : How many errors do people make, how severe are these errors, and how easily can they recover from the errors? Satisfaction : How pleasant is it to use the system? What is usability? Usability has five core components: http://www.useit.com/alertbox/20030825.html

Learning : How easy is it for people to accomplish basic tasks the first time they encounter a system?

Efficiency : Once people have learnt the design, how quickly can they perform tasks?

Memory : When people return to the system after a period of not using it, how easily can they re-establish proficiency?

Errors : How many errors do people make, how severe are these errors, and how easily can they recover from the errors?

Satisfaction : How pleasant is it to use the system?

People will go to great lengths to avoid using difficult systems. If they have to use a difficult system, they will do so as little as possible. If they have to use a difficult system, they will waste time. More support will be necessary. More changes will be necessary. Why is usability important? Bad usability costs money: In the same way, good usability can make money.

People will go to great lengths to avoid using difficult systems.

If they have to use a difficult system, they will do so as little as possible.

If they have to use a difficult system, they will waste time.

More support will be necessary.

More changes will be necessary.

Why is usability important? Bad usability can cost lives. What’s the largest threat to a nuclear power station?

Three Mile Island, 28 th March 1979. A mechanical fault caused a cooling system valve to stay open. A light in the control room indicated that power to open the valve was off. Engineers assumed that the valve was closed, when it was still open. The problem was not discovered for hours. Coolant leaked from the reactor. Caused a partial core meltdown. This is a bad thing. Why is usability important? Bad usability can cost lives.

Three Mile Island, 28 th March 1979.

A mechanical fault caused a cooling system valve to stay open.

A light in the control room indicated that power to open the valve was off.

Engineers assumed that the valve was closed, when it was still open.

The problem was not discovered for hours.

Coolant leaked from the reactor.

Caused a partial core meltdown.

This is a bad thing.

How does bad usability come about? A lack of communication between everyone involved in building the system.

We can’t remember everything. How does bad usability come about? Not understanding how people really use systems:

We can’t remember everything.

Our mental model of a how a system works is often not the same as reality. How does bad usability come about? Not understanding how people really use systems:

Our mental model of a how a system works is often not the same as reality.

We don’t make logical decisions; we choose the first reasonable option. Everyone makes mistakes, even experts. How does bad usability come about? Not understanding how people really use systems:

We don’t make logical decisions; we choose the first reasonable option.

Everyone makes mistakes, even experts.

How does bad usability come about? Not understanding how the design process works.

How can you improve usability? Don’t listen to people. “ To design an easy-to-use interface, pay attention to what users do, not what they say. Self-reported claims are unreliable, as are user speculations about future behaviour.” – Jakob Nielsen http://www.useit.com/alertbox/20010805.html Observe them.

Frequent, formal usability testing is best. If you can’t get or afford this, a few colleagues will do. You don’t need many of them: How can you improve usability? http://www.useit.com/alertbox/20000319.html Don’t listen to people. Observe them.

Frequent, formal usability testing is best.

If you can’t get or afford this, a few colleagues will do. You don’t need many of them:

Keep it simple. How can you improve usability? Avoid complexity and the paradox of choice: http://www.bt.com

Keep it simple.

Expose other options only when relevant. How can you improve usability? Avoid complexity and the paradox of choice: http://www.gmail.com

Expose other options only when relevant.

Provide people with constraints. How can you improve usability? Avoid complexity and the paradox of choice: http://www.kayak.com

Provide people with constraints.

Removed extraneous text and options. How can you improve usability? Avoid complexity and the paradox of choice: http://www.paypal.com

Removed extraneous text and options.

How can you improve usability? Provide people with feedback. http://www.kayak.com http://www.gmail.com http://www.twitter.com http://www.flickr.com

How can you improve usability? Show people the state of the system. http://www.amazon.co.uk http://www.flickr.com http://www.itunes.com

How can you improve usability? Allow people to easily recover from errors. http://www.gmail.com http://www.flickr.com

Usability concerns every object and system. Bad usability can be expensive and dangerous. Don’t listen to people. Observe them. You don’t need a lot of money or people to do usability testing. Usability is easy to improve. Summary Key points:

Usability concerns every object and system.

Bad usability can be expensive and dangerous.

Don’t listen to people. Observe them.

You don’t need a lot of money or people to do usability testing.

Usability is easy to improve.

Don’t Make Me Think! by Steve Krug Further reading Books:

Don’t Make Me Think! by Steve Krug

The Design of Everyday Things by Don Norman Further reading Books:

The Design of Everyday Things by Don Norman

useit.com – Jakob Neilsen AListApart.com BoxesAndArrows.com UXMag.com UXMatters.com Further reading Websites:

useit.com – Jakob Neilsen

AListApart.com

BoxesAndArrows.com

UXMag.com

UXMatters.com

Questions? http://www.flickr.com/photos/nzdave/491410298/