This paper proposes a cooperative search method by a user and a system (CEUS) for design problems involving both qualitative and quantitative objective functions.

In general Interactive Evolutionary Computation, a role assignment between a user and system and timing of user operation were determined and not changed during the search. In addition, although some methods for user fatigue alleviation by prediction have been proposed, the methods require a certain amount of learning data.

The proposed method allows the user to dynamically change search role allocation between the system and the user by user evaluation prediction and integration of interactive and non-interactive evolutionary computation, resulting in simultaneous optimization of qualitative and quantitative objective functions without increasing user fatigue.