Web data is characterized by a great structural diversity as well as frequent changes, which poses a great challenge for web applications based on that data. We want to address this problem by developing a schema-optional and flexible data model that supports the integration of heterogenous and volatile web data. Therefore, we want to rely on graph-based models that allow to incrementally extend the schema by various information and constraints. Inspired by the on-going web 2.0 trend, we want users to participate in the design and management of the schema. By incrementally adding structural information, users can enhance the schema to meet their very specific requirements.