usability lecture 05102010

What makes a site or a service usable?

Introducing usability

Today

� Introduction of the usability concept

� Usable websites� Usable websites

� Usability testing

� Usability assignment….

Introducing usability

What causes usability problems?

Usable websites

Usability guidelines….

Ohters…

� Welie.com

� Yahoo design patterns� Yahoo design patterns

� …. (just Google)

Usability testing

Usability testing…

Usability testing generally involves setting a series of tasks for

people to complete and noting any problems theyencounter – It’s as simple as that!encounter – It’s as simple as that!

Ways to test usability

What to do?

� Team up with a parnter

� Select 3-5 test participants� Select 3-5 test participants

� Minimum 2 tasks

� 30-50 min. each

� One of you is notetaker, one of you is moderator

Where to find participants

� Friends and family

� Co-students (not in this class)� Co-students (not in this class)

� …

Tell the participant…

� “We’re testing the WEBSITE, not you”

� “Think out loud as much as possible”� “Think out loud as much as possible”

� “Be brutally honest - we need your help!”

You, the moderator

� Don’t help them complete tasks

� Ask “Why” and “What are you thinking”� Ask “Why” and “What are you thinking”

� Answer questions with questions

Moderating questions…

� “What are you currently thinking?”

� “Describe the steps you’re going through here”� “Describe the steps you’re going through here”

� “What do you think will happen next?”

� “Is that what you expected to happen?”

� “That was confusing?”

� “And you were expecting ...?”

� “Would you mind repeating that again?”

Testing errors

� Not doing a proper run through of the test in advance

� Incomplete or buggy prototypes� Incomplete or buggy prototypes

� Not scheduling enough time between sessions

� Bad task design

� Accidental Revelation

� Getting frustrated or losing detachment

Wrapping up…

� Answer any questions they may have

� Thank them for their help and show them out� Thank them for their help and show them out

� Capture any important notes immediatly

� Prepare for the next test

Think aloud protocol

As the name suggests, you set a series of tasks and ask the

subject to verbalise their thoughts and feelings by ‘thinking

aloud’. The object of this is to gain valuable insight into the aloud’. The object of this is to gain valuable insight into the

thought processes behind the users actions.

Performance metrics

� Completion Rates – Are users able to complete the task?

� Time on Task – How long does it take users to complete?� Time on Task – How long does it take users to complete?

� Page Views – How many pages does it take to complete?

� Errors – The number and severity of errors per task?

� Satisfaction – How does the user rate the system?

Good and bad tasks

� Bad: Search for a bookcase

� Good: You have 200+ books in your fiction collection, � Good: You have 200+ books in your fiction collection,

currently in boxes strewn around your living room. Find a

way to organize them.

Testing plan

� Introduce the project

� State the goals of the test

� Profile your desired test subjects

� Outline your testing methodology

� Define your tasks

� Write a testing script

Example: www.ablongman.com/barnum/pdf/baitctestplan.PDF

Schedule

� Week 5: Introduction assignment & draft test plan

� Week 6: Feedback on test plan� Week 6: Feedback on test plan

� Week 8: Deadline test report & presetation

Sites to test….

� Do you know a (professional) site you would like to test?

� Search e.g.

http://www.uia.be/civicrm/profile?force=1&gid=5