This blog post is the second part in a series on web application usability. As stated in the previous post, users will get frustrated and stop using an application if it is not easy to use. In this series of blog posts some examples are given on improving the usability of web applications. These examples also hold for ‘normal’ websites, but are specifically important for web applications. In this specific blog post the topic is nonstandard scrollbars.

Nonstandard scrollbars
According to Jacob Nielsen in several applications, users missed many of the options because of nonstandard scrollbars. A scrolling control is a standard user interface element in application design, and (as always with usability) it should be designed in accordance with users’ expectations. As stated by Nielsen, users often overlook nonstandard scrolling controls, and thus never get to scroll the lists to see the hidden options. So only use scrollbars that actually look like scrollbars. Horizontal scrolling is another point to avoid. On the web, users only expect vertical scrolling and no horizontal scrolling. And like stated before, all standard design elements should meet user expectations.

According to Nielsen there are five essential usability guidelines for scrolling and scrollbars:

• Offer a scrollbar if an area has scrolling content. Don’t rely on auto-scrolling or on dragging, which people might not notice.
• Hide scrollbars if all content is visible. If people see a scrollbar, they assume there’s additional content and will be frustrated if they can’t scroll.
• Comply with GUI standards and use scrollbars that look like scrollbars.
• Avoid horizontal scrolling on Web pages and minimize it elsewhere.
• Display all important information above the fold. Users often decide whether to stay or leave based on what they can see without scrolling.

Next up in the series ‘Usability in web applications’ is the back button.