1. A computer-implemented method comprising: under control of one or more processors configured with executable instructions: forming a cluster for a plurality of web pages based on at least one similar characteristic of the plurality of web pages; automatically transforming data of the cluster to determine one or more occurrence vectors and one or more position vectors for data items of the plurality of web pages; determining a root template for the cluster based on the one or more occurrence vectors, the determining comprising identifying a tag path text item that appears in at least a threshold number of web pages in the cluster and appears once in each web page of the at least threshold number of web pages where the tag path text item is present; determining one or more detail templates for the cluster based on the one or more position vectors; and extracting structured information for the cluster based on the root template and the one or more detail templates.