Abstract: Automatically determining values for fields in an electronic document. In one embodiment, an intelligent form filler automatically fills in at least some of the fields based on as set of rules associated with a domain. A particular set of domain rules may have class definitions that define how to classify a field for that domain and group definitions that define how to group fields. The domain rules also describe how values can be determined for the fields, based on the classifications, groupings, and other factors. In one embodiment, the intelligent form filler submits more than one form such that different combinations of values are submitted. The values that were used to fill in the form(s) may be provided to an extraction tool, which use the values to facilitate extraction of information from a document returned in response to submitting the form.