1. A method for adapting the content structure of a portal, wherein said portal content structure is stored in a content model, wherein a user interface component is provided for controlling the layout of the plurality of pages rendered at said portal, and wherein a model management component comprises the functionality for performing persistent content model modifications, the method comprising: storing for a plurality of users participating in said method modification data records comprising history information indicating historic portal content model modifications performed by said plurality of users, wherein a modification data record further comprises a user identification of the modifying user, a page identification, an identification of the underlying modification operation and an identification of the portlet involved in said modification; performing a grouping of the plurality of users who by grouping users who performed similar or identical portal content model modifications, resulting in a plurality of groups, wherein each group comprises one or more user identifications, and each user identification is associated with a respective participating user; generating a set of personalized content model modification proposals from one of said modification data records, by selecting a group which comprises the user identification that is comprised of said modification data record and, for each of said users within the selected group: generating a personalized proposal data set based on data of said modification data record and the user identification of a respective user; and in response to receiving a request issued by a client on behalf of a user where the request is directed to the portal: retrieving at least one of said proposals associated with the requesting user; generating markup reflecting said at least one proposal; and sending said markup to a client browser associated with said requesting user.