# Maintaining the Sense of Agency in Semi-Autonomous Robot Conferencing
## 7 Discussion
### Sense of Agency  
The semi condition seems to maintain the sense of agency, but the auto condition decreased it from the tele condition. As described in the previous section, the degree of success in visual guidance was at a similar level in both the auto- and semi-conditions, but the consciousness of the subjects during visual guidance tended to be higher in the auto condition. This consciousness might decrease the sense of agency. In the semi condition, the total intervention time of the autonomous behaviors was approximately 30 s (20 times of 1.5 s) in approximately 180 s of teleoperation, but it was difficult for the subjects to notice the intervention. We considered that the visual guidance made the subjects believe that their guided gaze is an involuntary eye movement. Consequently, this belief might blur the border between the teleoperated and autonomous states. However, in the auto condition, because of the absence of ambiguity between these states, visual guidance would not work effectively.  
In the evaluation of the feeling of controlling the robot, the three subjects who noticed the visual guidance rated the semi condition lower than the tele condition. In the interview, they said that the behavior of the robot when reacting to a backchannel response to the speech of another answerer is unnatural every time. We thought that this is one of the social behaviors seen in multi-party conversation, but desirable social behaviors vary from person to person. If the autonomous behavior is not desirable to the operator, leading the teleoperation to this behavior would decrease the sense of agency.  
In the interview on the appropriateness of the behavior of the robot, several positive opinions on the semi condition were obtained. Three of the twelve subjects said that the robot seemed to give attention to both of the partners at a more appropriate timing than in the other conditions. Furthermore, one subject said that she was shy with strangers, and so it was difficult to look at the face of her partner. However, she also said that the facial movement of the robot seemed to imitate her behavior when she talks to her close friends. Thus, there is a probability that the operator can behave desirably without decreasing the sense of agency by using the semi-autonomous robot conferencing system.  
We expect that continuing semi-autonomous teleoperation makes the operator conduct desirable behavior even in a normal teleoperation and face-to-face conversation. Future work will examine this learning effect of the semi-autonomous robot conferencing system. Furthermore, examining the duration of the continuation of the sense of agency in the semi-autonomous robot conferencing is also a possible direction for future work.  
In the experiment, as both the audio and the live video feed were directly played without going through the network, there was almost no perceptible deviation or delay. On the other hand, there was a delay in the neck movement of the robot (1.5 s), as described in the Section 2. However, none of the subjects pointed out the motion delay of the robot. This is considered to be because if the neck movement of the robot is completely synchronized with the eye movement of the operator, the neck movement is too fast. Basically, an asynchrony between the movements of an operator and a robot is harmful for the sense of agency. Therefore, there is a possibility that this asynchrony that the eye movement of the operator reproduced as the delayed neck movement of the robot decreased the sense of agency. In order to produce the higher sense of agency, it is necessary to apply our proposed method that guides the behavior of the operator to the teleoperation interface, which synchronizes the views of an operator and a robot using a head-mounted display. For example, guiding the head movement of the operator using the hanger reflex may be effective. The development of a semi-autonomous robot conferencing system that yields a higher sense of agency is for a future work.