Improving Robot Behavior Optimization by Combining User Preferences

Recently it has been demonstrated that collaboration between automated algorithms and human users can be especially ef-fective in robot behavior optimization tasks. In particular, we recently introduced a Fitness-based Search with Preference-based Policy Learning (FS-PPL) approach, in which the algo-rithm models the user based on her preferences and then uses the model, along with the fitness function, to guide search. However, so far only interaction between a single human user and an evolutionary algorithm was considered. If multiple users contribute preferences, the algorithm must determine whether to model them separately or jointly. In this paper we describe an algorithm in which one evolutionary algorithm in-teracts with two users and determines the best way to model them automatically. We test the algorithm with automated substitutes for human users and show that it performs better for two users working together than for the same users work-ing separately, thus demonstrating the potential for crowd-sourcing robot behavior optimization