# An Adaptive UI Based on User-Satisfaction Prediction in Mixed Reality
###### Abstract  
As people begin to notice mixed reality, various studies on user satisfaction in mixed reality (MR) have been conducted. User interface (UI) is one of the representative factors that affect interaction satisfaction in MR. In conventional platforms such as mobile devices and personal computers, various studies have been conducted on providing adaptive UI, and recently, such studies have also been conducted in MR environments. However, there have been few studies on providing an adaptive UI based on interaction satisfaction. Therefore, in this paper, we propose a method based on interaction-satisfaction prediction to provide an adaptive UI in MR. The proposed method predicts interaction satisfaction based on interaction information (gaze, hand, head, object) and provides an adaptive UI based on predicted interaction satisfaction. To develop the proposed method, an experiment to measure data was performed, and a user-satisfaction-prediction model was developed based on the data collected through the experiment. Next, to evaluate the proposed method, an adaptive UI providing an application using the developed user-satisfaction-prediction model was implemented. From the experimental results using the implemented application, it was confirmed that the proposed method could improve user satisfaction compared to the conventional method.  
mixed reality; interaction satisfaction; satisfaction prediction; adaptive UI; human-virtual-object interaction 20222022022022020202202022020202020202202  
conduc [12; 13; 14; 15]. These conventional studies focused on proposing adaptive UI and evaluating the user satisfaction of the proposed adaptive UI. There were insufficient studies to provide real-time adaptive UI based on user satisfaction.  
In order to provide adaptive UI based on satisfaction, it is required to consider the satisfaction-measurement method. Most user satisfaction for MR applications is measured through a post-questionnaire [16; 17]. In this case, it is difficult to provide a real-time adaptive UI based on user satisfaction because a user answer is required. Meanwhile, it is also possible to analyze user satisfaction in real time by attaching a sensor such as an EEG to the MR-application user [18; 19]. However, in this case, there is a possibility that user satisfaction may be lowered due to the attachment of an additional sensor. As described above, the existing satisfaction-measurement method has a limitation that it is difficult to measure satisfaction in real-time or that satisfaction may be promised in the measurement process. That is, the existing methods are not suitable as a satisfaction-measurement method for providing a real-time adaptive UI based on user satisfaction. Therefore, it is required to study a new approach to provide a satisfaction-based adaptive UI.  
In this paper, we propose an adaptive UI based on user-satisfaction prediction in MR. The proposed method predicts user satisfaction based on interaction-related information such as gaze, hand, head, and object, and adaptively provides UI by correcting position based on the prediction results.  
This paper is composed as follows. In Section 2, we introduce interaction-related information that is mainly used in conventional studies and the developed adaptive UI in conventional studies. In Section 3, we propose an adaptive UI provision method based on user satisfaction in MR. In Section 4, we conduct two experiments, one is to develop the proposed method and the other is to evaluate the proposed method, and we analyze the experimental results. Finally, in Section 5, we present conclusions and future works.