Chapter 4 User InterfaCe DesIgn Best Practice A UI should be perceivable, operable, understandable, and robust. You should keep the main menu structure simple and consistent across layouts, and make sure it’s intuitive and easy to use. While keeping the layout simple, also make sure different elements are easily identifiable as primary buttons, secondary buttons, action items, or menu. You should group menu navigation based on user needs and mental model. Organize content into relevant groups and categories to increase its relevance: Perceivable: • You should review all color and contrast settings. • You should check alternative text applied to all nontext content. • You should provide a media alternative and description to each and every component. • Your content should be presented in a meaningful sequence. • Color is not the only visual means for conveying information; you should also check the shape, size, and content, and include animation. Operable: • Ensure navigation is consistent across pages and layouts, making users’ navigation easy. Match the navigation flow with the user mental model. • Content should be operable through a keyboard interface. • Check for missing headings and blank labels. • The purpose of each link should be determined from the link text alone. • Ensure focusable components receive focus in a meaningful order and a focus indicator is visible. Understandable: • Consistent navigation should be within a set of web pages. • Changing the setting of a UI component should not automatically cause a change of context. 140