Abstract. Essential to an audience driven website design philosophy is the organization of information and functionality according to the requirements of the different audience classes. However, at design time, it is often difficult to correctly assess the different needs and requirements of the different prospective users of a website. This may result in a non-optimal navigation structure, which will decrease the usability of the website. In this paper, we describe how to correct, at run-time and automatically, possible flaws in the design resulting from incomplete requirement assessment, using adaptive behavior. By observing the browsing behavior of the users, the requirements for the different users are validated and the website is adapted according to adaptation specifications made by the designer. These specifications express when and how the website needs to be adapted and are expressed using an Adaptation Specification Language. The work is presented in the context of an audienc...