Cognitive Walkthrough More evaluating with experts.
Post on 06-Jan-2018
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Cognitive Walkthrough
More evaluating with experts
Review
Discount evaluation techniques– Use experts to predict usability problems– Likely to be cheaper and faster with fewer ethical
issues Heuristic evaluation
– Experts identify potential problems in a design or prototype based on set of guiding heuristics
Cognitive Walkthrough
Assess learnability and usability through simulation of way users explore and become familiar with interactive system
A usability “thought experiment” Like code walkthrough (s/w engineering) From Polson, Lewis, et al at UC Boulder
Cognitive Walkthrough
Qualitative Predictive With experts
to examine learnability and novice behavior
CW: Process
Construct carefully designed tasks from system spec or screen mock-up
Walk through (cognitive & operational) activities required to go from one screen to another
Review actions needed for task, attempt to predict how users would behave and what problems they’ll encounter
CW: Assumptions
User has rough plan User explores system, looking for actions to
contribute to performance of action User selects action seems best for desired
goal User interprets response and assesses
whether progress has been made toward completing task
CW: Requirements
Description of users and their backgrounds Description of task user is to perform Complete list of the actions required to
complete task Prototype or description of system
CW: Methodology
Step through action sequence– Action 1– Response A, B, ..– Action 2– Response A– ...
For each one, ask four questions and try to construct a believability story
CW: Questions
1. Will users be trying to produce whatever effect action has?
2. Will users be able to notice that the correct action is available? (is it visible)
3. Once found, will they know it’s the right one for desired effect? (is it correct)
4. Will users understand feedback after action?
CW: Answering the Questions
1. Will user be trying to produce effect?– Typical supporting evidence
It is part of their original task They have experience using the system The system tells them to do it
– No evidence? Construct a failure scenario Explain, back up opinion
CW: Next Question
2.Will user notice action is available?– Typical supporting evidence
Experience Visible device, such as a button Perceivable representation of an action such as a menu
item
CW: Next Question
3.Will user know it’s the right one for the effect?– Typical supporting evidence
Experience Interface provides a visual item (such as prompt) to
connect action to result effect All other actions look wrong
CW: Next Question
4.Will user understand the feedback?– Typical supporting evidence
Experience Recognize a connection between a system response
and what user was trying to do
Let’s practice: My Internet Radio
User characteristics
Technology savy users Familiar with computers Understand Internet radio concept Just joined and downloaded this radio
Task: add a station to presets
Click genre Scroll list and choose genre Assuming station is on first page, add station
to presets -- right-click on station, choose add to presets from popup menu.
Click OK on Presets
Task:Click – Pick a genre
1. Will users be trying to produce whatever effect action has?
2. Will users be able to notice that the correct action is available?
3. Once found, will they know it’s the right one for desired effect?
4. Will users understand feedback after action?
Scroll list and choose genre
1. Will users be trying to produce whatever effect action has?
2. Will users be able to notice that the correct action is available?
3. Once found, will they know it’s the right one for desired effect?
4. Will users understand feedback after action?
Action: Right click on station and choose “Add to Presets”
1. Will users be trying to produce whatever effect action has?
2. Will users be able to notice that the correct action is available?
3. Once found, will they know it’s the right one for desired effect?
4. Will users understand feedback after action?
Action: Click OK
1. Will users be trying to produce whatever effect action has?
2. Will users be able to notice that the correct action is available?
3. Once found, will they know it’s the right one for desired effect?
4. Will users understand feedback after action?
Problems
Did I pick the right task? Or list out the right sequence of actions?
CW Summary
Advantages Explores important
characteristic of learnability
Novice perspective Detailed, careful
examination Working prototype not
necessary
Disadvantages Can be time consuming May find problems that
aren’t really problems Narrow focus, may not
evaluate entire interface
Your turn
Library - finding book
What are our tasks?
What are the actions?
CW: Questions
1. Will users be trying to produce whatever effect action has?
2. Will users be able to notice that the correct action is available? (is it visible)
3. Once found, will they know it’s the right one for desired effect? (is it correct)
4. Will users understand feedback after action?
CW: responsibilities
Design team creates prototype, user characteristics Design team chooses tasks, lists out every action
and response Experts answer 4 questions for every
action/response Design team gathers responses and feedback Design team determines how to modify the design
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