Abstract—In this paper, we clarify human perception of force by carrying out quality of experience (QoE) assessment in cooperation between two remote robot systems with force feedback. In the cooperation, robot arms of the two remote robot systems grasp both ends of each wooden stick, and then one side of the stick is moved only in one direction of front and back, left and right, and up and down. A user can perceive force sensed by a force sensor attached to the tip of the robot arm via a haptic interface device. Then, we investigate to what extent humans can accurately perceive the force direction via the haptic interface device. We also examine the influence of the length of the wooden stick on the human perception of force direction.