Yes you can, but only if you haven't completed the questionnaire (see Completing an Assessment).
If you want to change an answer for a particular question, simply go back to the question by:
- Using the "Previous" button at the bottom of the page,
- Using the Arrow Icons on left hand side to navigate among categories, or
- Using the left hand menu navigation and click on the question.
You'll see your current answer to that question in dark (colour depends on the Category you're in). You can select a new answer and that's it. Simple, isn't it? The application should take you to the next question.