Usability FAQ
Below are some commonly asked questions about usability:
What is Usability?
Usability is both a quality that indicates how easy a system is to use, and the methods of scientific investigation used to assess this quality. A system in this case can be anything a user interacts with. In usability, this is often web pages on the Internet, or on a company intranet, but it can also be consumer electronics devices or even ballots in a voting booth. As a quality it can be described in many ways, but these areas provide a good picture of what is investigated when UTEC performs a user test:
Utility:
- Does the system do what the users need it to?
- Can users accomplish what you need them to using the system?
Learning:
- How easy is it for a new user to become accustomed to the system?
- How easily can they perform tasks when they first start to use the system? Is there a steep learning curve?
Efficiency:
- If users have experience with the design or with a similar interface, how quickly can they perform tasks?
- Does the design help users avoid errors in their use of the system?
Satisfaction:
- What are the users' feelings about the system?
- If they don't enjoy using it, or find it unattractive, they will avoid it whenever they can.
Looking at all these areas as part of the design process, and redesigning to improve them is called user-centered design. Focus on your users will help both their experience, and your return on investment (ROI).
What is Formal Usability Methodology?
User testing should be an integral part of your design cycle. Whatever system you're making, you should test with your intended users early, and then test often as you continue through the design process.
UTEC has performed tests on web interfaces as early as the development of a simple paper prototype. Much like any other error in a development cycle, the earlier you catch it and rectify the situation, the smaller impact it will have on meeting your project milestones and your project budget. A major interface flaw will have the same effect as any major issue, and necessitate extensive redesign.
When embarking on a test, it is important to ask first who your users will be. The more specific an answer you can offer to this question, the better you can focus your usability tests. In addition, when you recruit users to test, you can choose individuals who have a better match with your expected user profile.
The second question to ask is what essential functions these users have to perform. Once you have broad tasks, such as 'buy our products' you can break them down into discrete actions that can be tested such as 'add the product to their shopping cart'.
Also important is establishing criteria for success and failure. While usability can be approached from a purely qualitative viewpoint, when testing a complex system or product of any sort, a more quantitative and scientific approach will yield results that will be easier to tabulate, and extract information from.
What is the Return on Investment?
Like any project, an exact cost figure can not be provided until it is known what needs to be tested. Factors that will increase the costs of testing include: large or very complex systems, systems with very specific users who are difficult to locate and recruit as test participants, and extensive testing programs.
One important fact to consider is that multiple usability tests throughout the course of the development cycle and education of designers in usability principles will cost a similar amount to a single larger test late in the development cycle. A single late test can also create additional expenses as products near completion reveal significant user weaknesses that necessitate major redesign.
It is worth noting that Jakob Nielsen suggests that roughly 10% of the development budget be expended on usability testing.
Return On Investment (ROI) and Usability Testing
Calculating ROI for usability testing can be as simple or as complex as you need.
For example, if you are managing a e-commerce site with a large number of users who exit the purchase process without actually spending their money, a better user interface will lead to more purchases. This simple improvement will lead to more revenue from your site. You can find more information about this in some of our case studies.
Another possibility could be the use of a product intended to function internally within your company, such as an intranet portal. An increase in usability will reduce time wasted by employees attempting to find information on the site, or perform essential work functions. The time saved for each employee may be small, but across your entire workforce as time passes the savings will add up to substantial sums.
A good user interface on a physical product can make the difference between good reviews of your product and good sales, or poor reviews and poor sales. Due to their inside knowledge about a product, designers can never have a full understanding of the user experience. Only usability testing can provide this essential information.
Two Examples of ROI Calculations
Both of these situations are hypothetical, but realistic.
- If you have 600 users making one error each day that costs five minutes (on average) to correct that can be prevented by revision of the user interface, you would save 150,000 based only on worker pay. (600 workers X 5 minutes each day X $10.00 an hour salary X 300 working days in a year)
- On an e-commerce site with 1000 visitors each day, a usability improvement in the shopping cart system could easily increase purchases by 5%. If buyers make an average of $100 in purchases, this single usability improvement would result in an increase of $1.75 million in revenue in one year (1000 visitors X 5% increase X $100.00 average purchase X 350 shopping days in a year)