This paper presents a concept of adaptive development of user interfaces in multimodal web-based systems. Today, it is crucial for general access web-based systems that the user interface is properly designed and adjusted to user needs and capabilities. It is believed that adaptive interfaces could offer a possible solution to this problem. Here, we introduce the notion of the user profile for classification, the interface profile for describing the system interface, and the compound usability measure for evaluation of the interface. Consensus-based methods are applied for constructing the interface profiles appropriate to classes of users.