1. A method for visual and interactive generation of wrappers for documents, and for automated information extraction comprising: defining extraction patterns on at least one example page, by visually and interactively selecting example-elements occurring on the example-page; visually and interactively declaring properties of the extraction patterns; generating a wrapper; applying the wrapper to at least one production document; and automatically extracting matching instances of the extraction patterns from the production documents wherein the processes of generation of a pattern further comprises: a) receiving from a user a pattern name and storing said name; b) creating and storing a filter for the pattern; c) visualizing the set of instances of the filter on at least one example document by evaluating the filter over the document and visualizing all data elements of the document that are matching instances, whereby a user can test the filter; d) modifying a previously created filter by adding to it refinement conditions that the instances of the filter must fulfill, where the refinement conditions are obtained from a user by receiving interactive commands from the user and where the refinement conditions are combined with those conditions for the filter that were added earlier; e) visualizing simultaneously all instances of all filters of the given pattern on at least one document by evaluating its corresponding pattern description against the document, whereby a user can test the pattern description constructed so far, wherein one of said refinement conditions is an internal condition expressing properties which the instances of a pattern must fulfill regardless of their context, wherein the representation of each of said filters is organized according to a logical conjunction of all conditions contributing to said filter, and where the representation of each of said patterns is organized according to the logical disjunction of all filters contributing to said pattern, whereby a pattern can be defined via successive narrowing and broadening steps corresponding to the addition of a new condition to a filter of said pattern, and to the addition of a new filter for said pattern, respectively.