Research-Based Web Design & Usability Guidelines


Citation: Research-Based Web Design & Usability Guidelines. 2011.

http://www.usability.gov/pdfs/chapter18.pdf

Key words: usability testing, observations, iterative approach, performance usability


This chapter is about (main discussion):
Creating prototypes, testing the prototypes, and then making changes based on the test results. The “test and make changes” process is repeated until the Web site meets usability goals. When these goals are met, the iterative process ends.

The author argues that:
the iterative design process helps to substantially improve the usability of web sites. Studies show that improvements made between original websites and redesigned ones “resulted in 30% more task completions, 25% less time to complete the tasks, and 67% greater user satisfaction. A second study reported that 8/10 tasks were performed faster on the website that had been iteratively designed. Lastly, a third study found that 46% of the original set of issues were resolved by making design changes to the interface.” (http://www.usability.gov/guidelines/guidelines_book.pdf 18:1)


The authors make the following statements or sites the following references on support of his/ her argument (provide 2-3 quotes):
it is best to perform iterative cycles of usability testing over the course of the web site’s development, as this allows developers the chance to observe and listen to many users.
http://www.usability.gov/guidelines/guidelines_book.pdf (18:6)
Performance usability testing with users early in the design process with a small number of diverse users (about 6 users ranging from novice to expert) is sufficient to identify problems with the info architecture and overall design issues. Once this has been completed, quantitative testing (measuring times, failure to find content, etc.) can be conducted. Try to achieve 95% confidence level in usability tests http://www.usability.gov/guidelines/guidelines_book.pdf (18:6)

The authors conclude that:
developing and testing prototypes through and iterative design approach creates the most useful and usable website.

The authors feel that:
“the iterative design process helps to substantially improve the usability of Web sites.”

References: http://www.usability.gov/guidelines/guidelines_book.pdf