Can usability be measured?
Can usability be measured?
Yes! You can measure usability and there is a range of metrics available to help you measure your design improvements. There are numerous measures that can help you find out if your improvements are:
- More efficient for users
- Easier to learn
- More satisfying to users
top of page
What can I measure?
Usability is typically measured by conducting usability testing. Learn About Usability Testing.
There are several measures of usability, including:
- Effectiveness
- Efficiency
- Satisfaction
- Ease of learning
- Memorability
- Error frequency and severity
To learn more about each of these measures, please see: What is usability?
The three most common factors measured in usability testing include: effectiveness, efficiency and satisfaction.
- Effectiveness: A user's ability to successfully use a Web site to find information and accomplish tasks.
- Efficiency: A user's ability to quickly accomplish tasks with ease and without frustration.
- Satisfaction: How much a user enjoys using the Web site.
top of page
What data should I collect?
There are two types of usability metrics that can be captured during a usability test. These metrics include:
- Performance data (what actually happened)
- Preference data (what participants thought)
In more formal, rigorous usability tests, we tend to rely more on performance data than preference data.
Performance data that can be captured include:
|
Performance Metric
|
Usability Measure
|
|
Successful completion rates
|
Effectiveness:
- Are users able to find information and accomplish tasks?
|
|
Time on task (or completion times)
|
Efficiency:
- Are users able to accomplish tasks quickly?
|
|
Number of pages viewed
|
Efficiency:
- How many pages do users visit before successfully finding information on the site?
- How does the number of pages viewed compare to the number of pages required to find the information?
|
|
Pathway or clickstream analysis
|
Effectiveness:
- Are users able to select the correct path to find information?
Efficiency:
- How lost do users become in the site?
- How many times does a user use the back button?
|
Preference data that can be captured include:
|
Performance Metric
|
Usability Measure
|
|
Subjective satisfaction
|
Satisfaction:
- Do users enjoy using the Web site?
|
|
User comments
|
Satisfaction:
- Are users frustrated or confused by the site?
|
|
Preference ratings
|
Satisfaction:
- Do users prefer a particular design?
|
top of page
How should I use the data?
Once you gather the metrics, you can use the data to evaluate the usability of your Web site and make recommendations for improvements.
- Conducting a baseline or benchmark usability test (usually conducted before design changes are made on your current Web site).
- Implementing recommendations based on the usability test and improving your current Web site to fix usability issues.
- Re-testing your Web site after the design improvements to measure the effectiveness of your improvements.
top of page
|
