Modelling Patterns for Deep Web Wrapper Generation

Interfaces of web information systems are highly heterogeneous. Additionally to schema heterogeneity they differ at the presentation layer. Web interface wrappers need to understand these interfaces in order to enable interoperation among web information systems. In contrast to the general scenario it has been observed that inside of application domains (e.g. air travel) hetergeneity is limited. More in detail web interfaces share a limited common vocabulary and use a small set of layout variants. Thus we propose the existence of web interface patterns which are characterized by these two aspects: the used vocabulary on the one hand and the common layout of pages on the other. These patterns can be derived from a domain model which is structured into an ontological model and a layout model. The paper introduces metamodels for ontological and layout models and describes a model driven approach to generate patterns from a sample set of web interfaces. We use a clustering algorithm to identify correspondences between model instances. This pattern approach allows for the generation of wrappers of deep web sources of a specific domain.