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Overview of Usability


What is usability?

Website usability is determined by user satisfaction, ease of learning, user ability to remember an organization and its functionalities, user effectiveness, efficiency and likelihood of errors while performing the tasks the site has been designed for. For example, finding the information needed or completing the e-commerce operation.

Usability is very much like quality: you typically notice it only when it is missing.
Sites that are not usable score poorly in:

  • Consistency of presentation and controls across the site
  • Logical and natural organization of information: clear structure, systematic labels, clear and meaningful labels
  • Contextual navigation: how much information is given for providing a context for the user (where is s/he in the site? where can s/he go? how can s/he go back?)
  • Efficient navigation: the amount of time and effort the user needs to exert in order to move around the site
  • Adequacy of feedback: are user interactions clear, are requests answered, do commands elicit the right response?
  • Searchability: how effectively the site content can be sought in search engines

Why usability is important?

A usable site greatly improves users' satisfaction, ability to learn and remember the site content and organization; it reduces errors, and leads to more effective and efficient user activity.

Usability is not the only important aspect of the site. Content, functionality and a website's popularity contribute even more to the success of a site. However, if users can do the same thing with two different sites, they will choose the one that is more effective, efficient and satisfactory.

Consider these benefits:

For an e-commerce site:

  • more efficient user tasks lead to better sales
  • increased satisfaction leads to increased trust and helps to build a company's brand
  • increased effectiveness, satisfaction and trust lead to increased customer loyalty, and to more repeated customers (who, on the average, spend more than first-time customers)
  • reduced errors and more effective user activities lead to a higher percent of successful transactions (at same cost of hardware and software)

For a portal:

  • increased effectiveness means that users quickly find what they need
  • increased satisfaction leads to increased trust and helps to build a company's brand
  • increased user efficiency means a higher percentage of successful operations

For an identity site of a company:

  • an enhanced image of the company, through an increased user satisfaction
  • a better user experience
  • increased user effectiveness

For an intranet:

  • increased efficiency of users (i.e. employees) leading to cost savings for the company
  • increased satisfaction leading to improved quality of work

Last but not least, many usability issues are also related to accessibility. In general, a usable web site is also more accessible. Disabled users (including those using low-bandwidth technology like cellular phones, PDAs, black and white screens, speaking browsers via telephones, screen readers) are not excluded from using it.

How to create a usable site?

Effective Information Architecture is the foundation for a successful website. To create good architecture, designers must focus on how the information is organized, the available navigation paths, and the interaction opportunities offered to the user.

In addition, the architecture and the content must be effectively presented to the user in order to:

  • Support common usage of the site
  • Keep the user motivated to continue using the site.

User-centered design is the only way to create usable websites. From the beginning of the project, the user should be the central focus of all development stages. Careful analysis of user-knowledge and needs, early prototypes of user interaction and information architecture, and user validation of prototypes are just a few preliminary steps that lead to an understanding of the content, functionality, architecture and presentation of the site.

Learn more:

Several evaluation methods can be adopted to validate and test a website (see

All methods require time, effort and competence to be carried out, and the often fast life-cycle of websites makes this process difficult.
While it is not equivalent to those methods, webtesting is the only method that can be used routinely, without incurring a major expense, whenever a major or minor change has been made to the website.

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