What is usability? This is what takes consideration of users, their goals, tasks and environment

Being a novice concept, usability is perceived in various ways. While some people regard it as a GUI attribute (which is either present or otherwise), others see it as a measure of convenience. Many think it is a separate branch of science with its instruments to achieve certain goals. All of them have a point, in a way. Usability is the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.

Definition of usability implies that it tackles a wide range of problems. It not only studies interfaces, but also does so with regard to GUI target users, taking into account their goals, tasks and environment. Which is sensible, because one cannot say if a GUI is convenient without knowing about its target users and their needs.

Examples to illustrate how usability works are numerous, i.e. an interface of a mobile phone that enables its target user to make calls and send SMSs conveniently might be perceived by the same target users as most inconvenient when listening to music or taking photos. Or, one group of target users (teenagers) can find an interface pleasant while middle-age users can describe it as complex and hard to understand.

Thus, enhancing usability of an interface to make it suit any user is pointless. It is only feasible when you keep in mind who are your target users and how they are going to use your product. This suggests a systems approach to GUI design when multiple aspects of usability are identified and analyzed separately.

Systems Approach in Relation to Users

Systems approach to GUI design must ensure that a variety of aspects, from technologies to be used to target user psychology and physiology, are taken into consideration, with as many nuances as possible.
In relation to the users aspects an interface designer should not forget about disparate groups of users whose GUI preferences might vary greatly.

For example, when designing a site one should think about:

• user ages
• user gender
• user education level\professional training
• users being visitors or company personnel

After marketing personnel provide user information, such as male/female ratio, user age, etc. an interface designer can categorize users and create interface requirements for each group. But at this point designers often forget about such an ‘invisible’ group of user as system administrators, site editors and moderators. In the case of a dynamic site, when content must be updated often and promptly, the effectiveness  and efficiency of interface is a key factor to effectiveness and efficiency of the site administrator or moderator. However, it occurs to often when a site can be easily used by its visitors, but not by its administrators simply because site management tools have not been observed at the design stage.

Why is it important?

Unlike site visitors, site moderators do not have much choice. When a visitor feels unhappy with site design or interface, he can click away from it to find another site (probably, you competitor’s). But ‘internal’ users cannot do so. When they need to add a news item or an article, they cannot use an alternative to do so. They have to use what was developed and often spend a lot of time to perform a simple operation.
So why invest both in external and internal interface? When you personnel have to struggle with a poor quality interface, they waste a lot of time and make numerous mistakes. In this case, interface is not only inefficient, but also a major principle of usability is forgotten that an interface should be subjectively pleasant.

Factors to Assess Usability

Quality of an interface can be assessed using the following factors that can be easily measured or calculated:

• Average operation time. Using a poor quality interface, your personnel can spend up to twice more time to perform an operation compared to a well-designed interface. When investing in a friendly and efficient interface you reduce time needed to work with software.
• Number of errors. How many mistakes occur when administering a site per month, such as incorrect prices, items missing form price lists, links that do not work etc.? How many users report such mistakes (if any)? All this is caused by poor design of software interface and can seriously endanger the health of your business.
• Learning time. How long does it take new personnel to learn administrative interface?

All this factors can be addressed when designing GUI thus improving company operations.

Today, many software vendors recognize the necessity to optimize user interfaces and take an end-user-oriented approach to GUI quality. Unfortunately, company personnel, i.e. users who are ‘on the other side’ are seldom given any consideration. When addressed properly, this aspect can help companies raise ROI of their software thanks to providing internal users with quality tools. Not only customers should benefit from a quality interface (which is now becoming an industry standard), but also the convenience of those who manage the system should be observed. Such multifaceted approach to GUI design can help to enhance system efficiency and improve usability level.

Rodion Ivanov, Anna Zheleznichenko