Cognitive Walkthrough

More evaluation without users

Project part 4

Please read the comments on your evaluation plans

Find participants Friends, neighbors, co-workers

Perform the evaluations Clearly inform your users what you are doing

and why. If you are audio or video recording, I prefer

you use a consent form. Pilot at least once – know how long its going

to take.

Part 4 write up

State exactly what you did (task list, how many, questionnaires etc.)

Summarize data collected Summarize usability conclusions

based on your data Discuss implications for the prototype

based on those conclusions

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: 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: 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: Methodology

Step through action sequenceAction 1Response A, B, ..Action 2Response 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

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?

Let’s practice: PAL

User characteristics

Technology savy users Familiar with computers Comfortable with basic cell phone

operations Familiar with many features of cell

phone, but not expert

Task:Party helper

Heather goes to a reception with some conference attendees. Heather doesn’t know many of them but wants to make a good impression since she’ll be looking for a job in a few months, so she wants to use PAL to remind her of names of folks she meets during the evening.

Action list

Assume PAL is running…

1. When introduced to someone new, press “earmark” button and repeat the name.

2. Assume no intervening introductions…

3. When there is a break, press and hold the back navigation button until bar reaches earmark.

4. Listen to name being repeated

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

Internet radio player

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?

Homework: last one

Cognitive Walkthrough of each other’s prototypes

Gather materials for your prototype:User characteristicstasks (1 or 2) and action listsStoryboard or running prototype

Perform CW for another group