An Approach to Conceptual Schema Evolution
In this work we will analyse conceptual foundations of user centric content management. Content management often involves integration of content that was created from different points of view. Current modeling techniques and especially current systems lack of a sufficient support of handling these situations. Although schema integration is undecideable in general, we will introduce a conceptual model together with a modeling and maintenance methodology that simplifies content integration in many practical situations. We will define a conceptual model based on the Higher-Order Entity Relationship Model that combines advantages of schema oriented modeling techniques like ER modeling with element driven paradims like approaches for semistructured data management. This model is ready to support contextual reasoning based on local model semantics. For the special case of schema evolution based on schema versioning we will derive the compatibility relation between local models by tracking dependencies of schema revisions. Additionally, we will discuss implementational facets, such as storage aspects for structurally flexible content or generation of adaptive user interfaces based on a conceptual interaction model.