1. Chapter 21 Deciding on what you need to evaluate: the strategy

2. Creating an Evaluation Strategy
What Is the Purpose of This Evaluation?
Does system meet usability requirements/concerns
Qualitative Usability Requirements
Desired features
“The users on an e-shopping site should be able to order an item easily and without assistance.”
“Railway clerks work in extremely noisy environments, so any warning messages to them should be visually distinct and highlighted on the screens.”
UIDE Chapter 21

3. Creating an Evaluation Strategy
Quantitative Usability Requirements/Usability Metrics
Explicit measures used: percentages, timings, or numbers are used.
“It should be possible for the users to load any page of a web site in 10 seconds using a 56K modem.”
“It should take no more than two minutes for an experienced user (one who has domain knowledge and has undergone the prescribed level of training when the new system is introduced) to enter a customer’s details in the hotel’s database”
UIDE Chapter 21

4. Creating an Evaluation Strategy
Prioritizing Usability Requirements and Concerns
The usability requirements most important to the success of the system are given priority.
Assign values to the five dimensions of usability, the Five Es.
UIDE Chapter 21

5. UIDE Chapter 21

6. Online Museum Exhibition
UIDE Chapter 21

7. General Museum Site
UIDE Chapter 21

8. Creating an Evaluation Strategy
What Type of Data Do I Want to Collect?
Quantitative data
Numeric content
Qualitative data
Non-numeric content
UIDE Chapter 21

9. What Constraints Do I Have?
What Am I Evaluating?
What Constraints Do I Have?
Money
Timescales
Availability of usability equipment
Availability of participants and the costs of recruiting them
Availability of evaluators
Documenting the Evaluation Strategy
UIDE Chapter 21

10. UIDE Chapter 21

11. The Global Warming UI: The Evaluation Strategy
Deciding What to Test
Do You Have to Work within Any Constraints?
Writing Up Your Evaluation Strategy for the Global Warming Evaluation
UIDE Chapter 21