Abstract: A data processing system uses a machine-generated data structure (MGDS) to dynamically record and use the character recognition and repair histories of category fields on a document form. The MGDS includes a field data segment which has a coded data buffer portion and an error buffer portion for the extracted field image. Recognition coded data is entered into the coded data buffer portion and recognition error data is entered into the error buffer portion of the field data segment. Then subsequent repair processes can be applied to the recognition coded data by augmenting the MGDS with a repair segment for each character string which is repaired. A sequence of repair stages can be applied to a particular character string, each repair step adding another repair segment to the MGDS. At each stage of repair, the best estimate of the character string is placed into the coded data buffer portion of the field data segment.