To get the most out of AJAX, you need to identify and target the areas where it will have the most effect and then take steps to monitor that effect. AJAX can be used in most any Web site design, but it's most effective when used to speed up searching and multistep processes. For solving simple problems, just picking appropriate areas to apply AJAX will give good results. However, as complexity increases, you'll want to add instrumentation to your applications to get hard data on the changes AJAX is causing. Using this data, you can fine-tune your approach and start down the path to effective AJAX. The final step in using AJAX effectively comes from looking at the usability of the graphical interfaces you're creating; we'll cover this process in the next chapter.