Reverse value attribute extraction

An attribute manager extracts attribute values from formatted data. The attribute manager maintains information concerning a plurality of attributes, such as matching names and values for attributes. Formatted data is parsed into a plurality of elements comprising a canonical representation of the data, independent of the data format. The formatted data. can be, for example, a web page, a portable document format document or a word processor document. The attribute manager scans the elements for occurrences of attribute values. Based upon value occurrence distribution and frequency within the data, and maintained information concerning attributes, the attribute manager infers occurrence of specific attributes in the formatted data and assigns the most appropriate occurring values to the specific attributes. In some embodiments, the attribute manager stores attributes and their assigned values, and uses this information to automatically prepare summaries of input data.