1. A computer-implemented method of extracting a datapoint from a markup language document using multiple extraction rules, the method comprising: applying a first extraction rule to a structural graph representation of the markup language document to generate correlation values for each of a plurality of nodes of the structural graph representation; applying a second extraction rule to the structural graph representation of the markup language document to generate correlation values for each of the plurality of nodes of the structural graph representation; and analyzing the correlation values generated via application of the first extraction rule, in combination with the correlation values generated via application of the second extraction rule, to select, from the plurality of nodes, a single node from which to extract the datapoint, said analyzing performed by a computer.