PURPOSE: To attain the unitary control for the conference data by sending the data change information including the additional descriptions and corrections carried out by a device of the data receiver side to a device of the data sender side and performing the unitary control of data at the data sender side.

CONSTITUTION: When an electronic conference is held with use of the conference data stored in a device A, the device A adds the address of its own and the intra-device data control numbers to the data during the conference. These data are held in the device A and at the same time distributed to the devices B and C as shown by the thick arrows 1, 2 and 3 via the communication channels. In such a way, the address of a data sender (device) A, the data numbers that can specify the data, etc., are added to the conference data to be distributed in order to uniquely specify the data to the conference data in a system. Thus the data receivers (devices) B and C transmit the data change information to the sender A if the sender A corrects the distributed data. The sender A performs the unitary control of the original texts based on the information.