Usability is an attribute that evaluates how easily and conveniently customers can use web interfaces. The efficiency of a website is largely determined by its usability[ CITATION Nie07 \l 1033 ]. Websites should be user-friendly and appealing. Users have access to numerous sites through the web and they are hence spoilt for choice. Consequently, it is very unlikely for customers to visit a poorly designed site. A website with good usability is one that is easy to use, one whose homepage clearly states what a business/company offers and what clients can do on the site, and one whose information is easy to read and answers clients' key questions.
Usability is important in attracting potential users and in retaining current users. It ensures that users find the information they are looking for, spend less time in finding the information, and have fun in the process. Usability guarantees employee productivity in the case of intranets since users will spend less time in trying to figure out how and where to find relevant information.
To ensure that a website is usable and designed appropriately, it is important to involve prospective users in its design. Before launching a website, designers should seek feedback from potential customers. Many companies have reaped tremendous benefits from incorporating suggestions from potential users, which helped in improving the quality of their websites[ CITATION Coy01 \l 1033 ]. In web design, usability implies that the web designers are very proficient in constructing a website. In comparison to other quality areas, designers generally spend more on ensuring a website’s usability. Presently, approximately 10 % of the budget of constructing websites is spent on resolving and improving usability.
The following criteria are appropriate for assessing usability:
i. Efficiency; The ability of users to complete tasks after learning the website’s design.
ii. Learnability; The ability of users to perform basic tasks easily the first time they access the website.
iii. Satisfaction; The enjoyment derived from using the web design.
iv. Memorability; The ease with which users can reestablish proficiency when they return to the website after not using it for a while.
v. Errors; The likelihood of making errors on the website, the severity of the errors and the ease with which the errors can be rectified.
vi. Accessibility; Users should be able to easily access appropriate information on the website.
vii. User-friendly design; There should be a good balance between the graphics and texts on a website such that there is good flow of information[ CITATION Hil05 \l 1033 ]. The website should be appealing to the target audience and the navigation aids should be easy to access.
Judgments on the usability of a website and suggestions to improve usability should be made by prospective as well as current users. Prospective users should be involved in testing the usability of a website before it is launched. Current users on the other hand should be allowed to provide feedback on their experience in using the site. User testing is the most essential and useful method of determining usability. This method should be performed in 3 steps:
1. Finding representative users, for instance, clients for an e-commerce website
2. Asking the users to complete representative tasks on the website.
3. Observing how the users perform the tasks, where they are successful, and where the user interface presents difficulties for them.
4. Listening to and documenting responses from the users as regards their experience in using the site.
The profile of the representative users who take part in the testing process should suit that of the target audience for the website. The users should be guided through the testing procedure and they should be given in real-life tasks. The test sessions should be carried out in a quiet and serene environment where users can concentrate without destructions. Web designers should use the feedback and responses provided by the representative users to make appropriate changes and corrections to improve usability. Occasionally, precise information may not be obtained from surveys, and sometimes the information provided may be misleading.
Some problems that could come up during user testing are;
1. Obtaining similar results from two or more users. This can be resolved by having one user at a time to test the website or placing the users in different rooms.
2. Obtaining irrelevant outcomes from the testing procedure as a result of engaging users who do not fall in the target group for the website. This can be resolved by interviewing the users and asking them basic questions before the testing procedure to ascertain if they fit the profile of the target group.
3. Users can get influenced if they are told what to do hence real-life simulation can fail to be achieved. When carrying out the test, designers should be quiet and let the users to do the talking.
Disagreements about usability should be resolved through discussions and further testing. If designers disagree on a particular aspect, they should discuss among themselves and reach a consensus. Continuous user testing should also be carried out after launching the website to ensure that usability is fully achieved.
Coyne, K., & Tahir, M. (2001, February 6). Make It Usable. Retrieved May 26, 2011, from pcmag.com: http://www.pcmag.com/article2/0,2817,33821,00.asp
Hillman, D. (2005). Assessing Usability. Retrieved May 26, 2011, from ThePlace: http://dhillman.com/theplace/webdevel/assessing_usability.htm
Nielsen, J. (2007). Usability 101: Introduction to Usability. Retrieved May 26, 2011, from useit.com: http://www.useit.com/alertbox/20030825.html