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 data record further comprises the user identification of the modifying user, the page identification, the identification of the underlying modification operation and the identification of the portlet involved in said modification; performing a grouping on said plurality of users applying the criterion of similar or identically performed portal content model modifications, resulting in a number of groups, wherein a group comprises one or more user IDs associated with respective ones of said plurality of participating users; generating a set of personalized content model modification proposals from one of said modification data records, by selecting the group which comprises the user ID that is comprised of said modification data record and doing for each of said users comprised of said selected group: generating a personalized proposal data set based on data of said modification record and the personal user ID of a respective user of said selected group; and when 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 the client browser associated with said requesting user.