At this point, we have examined the basics of what it takes to create Ajax web applications—the standards that are used, the design patterns to follow, the server-side languages available, the frameworks, and the Document Object Model (DOM) methods and properties used to fetch data and manipulate the DOM. However, we have not discussed how to design the interface to your application. Just as important as the tools that go into building an application are the components that make up the user interface.
The interface is how the end user (your main focus) interacts with and uses the application you have designed. Unless you design the interface with the user in mind from the beginning, parts of your application may be cumbersome to navigate, agitating people and discouraging them from using your Ajax web application in the future.
Fortunately, there are ways to prevent this from happening. In addition to the general rules we created more than 15 years ago for desktop applications, other suggestions and guidelines were created specifically for web interfaces. With these as your guide, you should have no problems designing an interface that people find useful and enjoy interacting with.
Designing Ajax interfaces covers four distinct yet related components: usability, functionality, visualization, and accessibility. By considering each component and the nuances they bring, you will design and create an application that users find intuitive, user-friendly, ...