An editing system having a dialogue operation type interface directs a next operation by referring an operation history. User information is inputted by using speech input/output, pointing by a finger and 3-D CG. A human image representing the system is displayed as an agent on the image output device, and a user error, availability to a queue and a utilization environment are extracted by the system and informed to the user through the agent. The system responds to the user intent by the image display or the speech output by using the agent as a medium so that a user friendly interface for graphics edition and image edition is provided.