While usability tests can be either observation-based or interview-based, they most often involve a potential user using, reacting to, and thinking aloud as they grapple with a particular product, interface, or design prototype. These tests provide concrete information regarding the exact problems users encounter with the item or interface while they are being encountered.
Why do we evaluate? We aim to create systems that never fail for people. We’re not evaluating people. Instead, people help us evaluate our designs, allowing us to identify fragility or failure points early enough in the process to fix them before they become irreversible.
Usability Testing resolves such questions as:
- Does the design satisfy the user’s goals and expectations?
- Does it fit the user’s context?
- Is it usable?
With usability evaluations we can also:
- Compare multiple or competing designs
- Check the design solution against the user requirements
- Solve design disputes with data
- Overcome the “expert blind spot”
- Build confidence that your new design will be well received
Usability Measures
There are many different measures for evaluating design solutions. The questions we ask and the kinds of things we want to find out determine which measures we use. The more common
include:
- Efficiency
Efficiency can be measured by replicating user tasks and measuring the time it takes users to complete them. - Effectiveness
Effectiveness can be measured through direct observation of users as they interact with products and systems. - Experience
Experience extends beyond the more quantifiable measures and delves into how people feel‚ their emotional and intellectual reactions, and the frustrations and satisfactions they encounter during the user experience.