Usability Evaluation Principals

Usability evaluation focuses on how well users can learn and use a product to achieve their goals. It also refers to how satisfied users are with that process. To gather this information, practitioners use a variety of methods that gather feedback from users about an existing site or plans related to a new site.

What is Usability?

Usability refers to the quality of a user's experience when interacting with products or systems, including websites, software, devices, or applications. Usability is about effectiveness, efficiency and the overall satisfaction of the user.

It is important to realise that usability is not a single, one-dimensional property of a product, system, or user interface. ‘Usability’ is a combination of factors including:

• Intuitive design: a nearly effortless understanding of the architecture and navigation of the site.
• Ease of learning: how fast a user who has never seen the user interface before can accomplish basic tasks.
• The efficiency of use: How fast an experienced user can accomplish tasks.
• Memorability: after visiting the site, if a user can remember enough to use it effectively in future visits.
• Error frequency and severity: how often users make errors while using the system, how serious the errors are, and how users recover from the errors.
• Subjective satisfaction: If the user likes using the system.

 What are the Evaluation Methods?

The key to developing highly usable sites is employing user-centred design. The expression, “test early and often”, is particularly appropriate when it comes to usability testing. As part of UCD, you can and should test as early as possible in the process and the variety of methods available allow you to assist in the development of content, information architecture, visual design, interaction design and general user satisfaction.

Opportunities for testing include:

• Baseline usability testing on an existing site.
• Focus groups, surveys or interviews to establish user goals.
• Card Sort testing to assist with IA development.
• Wireframe testing to evaluate navigation.
• First, click testing to make sure your users go down the right path.
• Usability testing to gauge the user interaction end-to-end and.
• Satisfaction surveys to see how the site fares in the real world.

Anyone or a combination of these tests will radically improve the usability of your site, system or application.

Content for this article is prepared by the Digital Communications Division in the Department of Health and Human Services (HHS) Office of the Assistant Secretary for Public Affairs.