Iteration and constantly re-examining your decisions are part of the process. The design process is not always predictable, and may not always run like a well-oiled machine.
Asking More Questions
You might find yourself stepping back and doing more research because you had a sudden realization partway through the interaction design phase. Or you might find yourself going back to the information architecture phase because usability testing revealed a fatal flaw in the site’s organization. Don’t worry, this is normal. But it’s important to keep trying. Knowing what doesn’t work for your site can only help you find out what does work.
A Process and a Philosophy
User-centered design is both a process and a philosophy. Unfortunately, spending time and money doing design work is sometimes a thankless task, because most people don't notice when a site has good usability. They only care when the site seems broken to them!
Providing a great user experience is an ongoing process that never ends, and it’s hard to find a web site you can’t improve upon in some way. With the right amount of skill, insight, testing, and determination, you’ll end up with a site that provides a great user experience, and your users will thank you for it.