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Introduction to HCI Monday April 6 th For today . . . Atomic Chef—”Titanic’s Wake,” Tom Kujala, Brian Lewis, and Emelie Hegarty I received a video Let’s talk about prototypes and scenarios Let’s look at performance based testing Be sure to sign up for prototype-presentation spots
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Introduction to HCI Monday April 6th
For today . . . • Atomic Chef—”Titanic’s Wake,” Tom Kujala, Brian Lewis, and Emelie Hegarty • I received a video • Let’s talk about prototypes and scenarios • Let’s look at performance based testing • Be sure to sign up for prototype-presentation spots
The Atomic Chef”Titanic’s Wake,” Tom Kujala, Brian Lewis, and EmelieHegarty
I received a video. It’s funny, but a little rough.You have about 45 seconds to leave the room if you want. http://www.youtube.com/watch?v=8AyVh1_vWYQ
Let’s Look at Prototypes (and rapid prototyping)
Scenarios One method of “discount usability evaluation”
Types of Prototypes Different Features Horizontal prototype Scenario Functions Full system Vertical prototype
Scenarios: The Ultimate Minimalist Prototype • Describe a single interaction session with no flexibility for user • Combine limitations of both horizontal and vertical prototypes
A Scenario is an Encapsulated Description of: • An individual user • Using a specific set of computer facilities • To achieve a specific outcome • Under specified circumstances • Over a certain time interval
Design choices Thinking about ways to make your prototype work for your audience
Say, for example, that part of your interface used three buttons Start Record Stop
If you found that your audience was made up of older people, you might increase font size Start Record Stop
If you determined that your audience might need some help Start Record Stop
If you determined that they might need some more help Start entering data Record information in database Stop entering data
If the audience was kids Go Do it Stop
Producing Faster Prototypes • Place less emphasis on efficiency. • Accept less reliable or poorer quality code. • Use simplified algorithms. • Wizard of Oz study. • Use a different computer system than the final platform. • Use low-fidelity media • Use fake data and other content. • Use paper mock-ups. • Use an imaginary (verbal) prototype.
Performance-Based Usability Testing Users perform tasks; we observe what they do
Selecting Tasks to Test • Most frequently done tasks • Most important or critical tasks • Most complex tasks
Method • Tell users what you want them to do • Make sure they are familiar with the equipment and procedures • Make sure they know that they are not on trial and can leave at any time • Be unobtrusive • Record observations; debrief them at the end
What Can Be Observed • Objective measures • Subjective measures
Objective Measures • Success or failure • Time to complete • Number of errors made • Pages or Help screens referred to • Calls to a Help Desk
Subjective Measures • Apparent satisfaction • Confusion • Anger and frustration
Talk-Aloud Protocols Sometimes called “Think-Aloud Protocols”
Method • People are asked to perform a task • While they are performing it, they say out loud what they are thinking • Test coordinator records what is said • After they are done, they may be asked additional questions
Benefits • You can learn where and why people get confused • People may offer a solution within their thought process • You can get a lot of information
Drawbacks • Not everyone is good at doing something and talking about it at the same time • People will not want to appear stupid • If it doesn’t work, it usually fails Big Time
Developing Questionnaires Post-test questionnaires Surveys--on-line or in-person
Questionnaires • A chance to gather additional information • A chance to do follow-up questioning • An opportunity to waste time and appear foolish
Some Guidelines • Don’t ask questions for which you already know the answer • Don’t ask questions that would be better asked by observation • Make sure questions are fairly stated (neutral) • Don’t ask for too much of people’s time
Types of Questions • Multiple choice • Likert scale • Open-ended A mixture of types is usually good
Multiple Choice • People select from a limited set of choices (yes/no, 0-2/3-5/more than 5) • Make sure choices are mutually exclusive and clear • Make sure questions are meaningful
Likert Scale • On a scale of 1 to . . . . • Odd/even number of choices? • Balance around the mid-point • Meaningful labels for numbers
Open-ended Questions • A chance to get additional information and opinions • Allow enough space for answers • Make sure your questions are clear and unambiguous
? Shall we try one
Preparing for the Test • Consider www.rpi.edu (and pages it links to) • Design a scenario to test the effectiveness and usability of the site (the choice of scenario is up to you—make it a good one) • Design an observation sheet of things you will observe • Design a debriefing questionnaire
Conducting the Test • We’ll select several groups • Each, in turn, will conduct the test at the front of the room • We’ll all observe the test and learn from our observations
Each Group Will . . . • Conduct the test • Hold a debriefing • Tell us what they observed • Share some preliminary thoughts on applying the results of the test
On Thursday . . . We’ll talk about prototypes and hear from Sean McLoughlin and Brendan Cass about “Driven to Distraction?
Go forth and perform