1. A document processing apparatus comprising: an input device; a display device; a processor; a memory device which stores a plurality of instructions, which when executed by the processor, cause the processor to operate with the display device and the input device to: (a) detect video data designation information attached to electronic document data, the electronic document data including: (i) a first element having a first central activation value used to generate an index; (ii) a second element having a second central activation value used to generate said index; and (iii) read out audio attribute information; (b) generate a summary of said electronic document data, wherein said generation of said summary includes spreading said first central activation value to said second central activation value; (c) select video data in accordance with said detected video data designation information; (d) store a categorization model, the categorization model including a plurality of data categories; (e) create an automatic categorization based on any one of said video data and electronic document data in accordance with the categorization model; (f) update the categorization model with the automatic categorization; (g) control an output of said summary of said electronic document data such that said summary of said electronic data being output is automatically progressed based on at least one of a size of a display area and a length of time displayed; (h) control an output of said selected video data in correspondence with the output of said summary of said electronic document data such that said selected video data being output is output in synchronization with said progress of the said operation of outputting said summary of said electronic data; (i) control an output of a read out audio based on read out audio attribute information in said electronic document to synthesize said read out audio; and (j) automatically terminate the output of said video data upon completion of the outputting of said summary of said electronic document data regardless of whether an end of the video data has been reached.