A method is provided for information extraction from among a multiplicity of documents each having a corresponding document object model (DOM) comprising: computing signatures associated with nodes of a multiplicity of DOMs corresponding to the multiplicity of documents; producing an index that associates computed signatures to each document that has a DOM that has one or more nodes corresponding to such signature; annotating one or more nodes of a DOM that corresponds to the at least one selected document; wherein the one or more annotated nodes respectively correspond to one or more respective signatures included in the index; and matching the signatures that correspond to the annotated nodes with signatures in the index to determine which documents from the multiplicity of documents have one or more DOM nodes that correspond to one or more of the annotated nodes.