The invention relates to a data processing apparatus and a data processing method. The data processing apparatus allocates a page number in a record to each of a plurality of records of a variable data print job and performs a preflight check every page number. After that, the data processing apparatus extracts the records in which the same kind of (or same) problem has occurred in a page of the same page number from the records included in the variable data print job. The data processing apparatus calculates a ratio of the extracted records to all records having the page of the page number and presumes whether the problem relates to a master object or relates to a variable object according to the ratio. The data processing apparatus displays whether the problem in the page relates to themaster object or relates to the variable object every page having the problem.