Web site usability is the quality of a user’s interaction with a web site or, in other words, how usable a web site is to the user. Ultimately, users want to be able to easily access a web site and determine how to use it within seconds.

Usability influences whether many users will return to a web site, how often they will use the web site, and how happy they are with their overall experience at the web site. There are millions of sites on the Internet and they are all in competition for users’ time and attention. Users get their expectations for usability from the best of all of these other sites.

• Design is a key determinant to building online trust with consumers. For motivated users of an information site, bad design (busy layout, small print, too much text) hurts more than good design helps.
• Layout on a web page (whitespace and advanced layout of headers, indentation, and figures) may not measurably influence performance, but it does influence satisfaction.
• Experience matters: Blue links are easier to click than black ones, even though black ones have higher visual contrast and are easier to see.
• It’s important to consider the users when you have a choice of icons, links, or both. Initial performance is best with the link alone. Frequent users can use either equally effectively. Icons are not faster, relative to text links alone. –
• Rules of thumb for icons: Make them as large as feasible, place frequently used icons in a persistent task bar, and arrange them either in a square (first choice) or in a horizontal layout.
• The acceptance and impact of animation is enhanced when users are warned to expect it and allowed to start it when they want.
• Use of whitespace between paragraphs and in the left and right margins increases comprehension by almost 20 %.
• A format of 95 characters per line is read significantly faster than shorter line lengths; however, there are no significant differences in comprehension, preference, or overall satisfaction, regardless of line length. –
• Applications vs. websites: In general, visual layout guidelines for GUIs also apply to the web, but there are differences to be aware of. For example, dense pages with lots of links take longer to scan for both GUI and web; however, alignment may not be as critical for web pages as previously thought.
• Narrative presentation enhances comprehension and memory. Narrative advertisements produce more positive attitude about the brand and a higher incidence of intent to purchase.
• On sites with clear labels and prominent navigation options, users tend to browse rather than search.Searching is no faster than browsing in this context.
• Users will wait longer for better content. Users will wait between 8-10 seconds for information on the web, depending on the quality of the information.
• Consumer purchase behavior is driven by perceived security, privacy, quality of content and design, in that order.
• Users have clear expectations about where to find the things they want (search and back-to-home links) as well as the things they want to avoid (advertising).