7. The computer-implemented method of claim 1 , wherein extracting the hidden attributes comprises: segmenting text associated with the at least one web document from which one of the stitchable tables was extracted to obtain at least two segment sequences, wherein the segment sequences comprise segments; scoring possible segment alignments between the at least two segment sequences; and aligning segments between the at least two segment sequences based on the scoring of the possible segment alignments to obtain aligned segments.
8. The computer-implemented method of claim 7 , wherein segmenting the text uses at least one heuristic to generate the segments, and wherein the at least one heuristic is selected from the group comprising: punctuation, html-tag separators, longest common subsequences, and a link between the text and an entity repository.