During the wrapping of web interfaces ontological know-ledge is important in order to support an automated interpretation of information. The development of ontologies is a time consuming issue and not realistic in global contexts. On the other hand, the web provides a huge amount of knowledge, which can be used instead of ontologies. Three common classes of web knowledge sources are: Web Thesauri, search engines and Web encyclopedias.

The paper investigates how Web knowledge can be utilized to solve the three semantic problems Parameter Finding for Query Interfaces, Labeling of Values and Relabeling after interface evolution. For the solution of the parameter finding problem an algorithm has been implemented using the web encyclopedia WikiPedia for the initial identification of parameter value candidates and the search engine Google for a validation of label-value relationships. The approach has been integrated into a wrapper definition framework.