# Virtual Reality as a Reflection Technique for Public Speaking Training
## 1 Introduction  
The act of speaking in public can trigger fear for speakers of all levels. It is common that people with conditions, such as autism spectrum disorder (ASD), have a pronounced tendency for anxiety. However, according to statistics, approximately 77% of the general population are afraid to speak in public, which makes public speaking the most common social fear [1, 2]. The fear and tension may compromise the quality of a presentation. For example, the inner state of a presenter has a significant influence on the presenter's cognitive resources, eye movements, body postures and the vocalization of hand movements at the time of the presentation. In general, people try to undertake repetitive practices before the actual presentation in order to control their own inner state and behavior. However, even though the best training method is to rehearse the presentation in a similar environment, the cost of the preparation is generally high. Hence, a simpler method is desirable.  
Recently, a number of presentation training programs that use virtual reality (VR) technology have been proposed, in which a realistic situation can be reproduced at a low cost with 3D models in a virtual environment [3, 4]. By using a VR system, the users can improve their presentation skills as much as they want without worrying about feedback from others [5, 6]. Many of these existing VR-based training systems evaluate a presenter's behavior during training and provide feedback during or after the presentation. It is proven that these systems have certain effects on improving presentation skills.  
While many of the existing studies apply VR to exposure training that aims to improve public speaking skills while reducing anxiety, this study emphasized self-reflection as an important technique. Video-reflection has been proven to be a useful pedagogical tool for basic training on public speaking. The nonverbal and verbal elements of speaking performancescan be recorded for subsequent review and analysis. This technique helps individuals improve their skill acquisition, speech content, objective test performance, and the recall of the actual speech [7]. In addition, this strategy reduces the anxiety and perceived social costs of speakers, and increases the positive appraisals of the performance [8; 9]. However, people with public speaking anxieties usually have low self-esteem and little self-confidence, and they are more likely to avoid videotaped feedback because they are unwilling to watch their own performance [10].  
To overcome this disadvantage, a simple VR-based reflection system was explored in this study. This reflection system involves VR and a head-mounted display (HMD) to enable presenters to observe their own behavior from a third-person's perspective in the 3D VR environment, which could be reflected by an increase in subjective ratings of observer-like perspectives during remembering [11], and to provide a wider field of view (FOV) to change the spatial awareness compared to video, so that a better self-reflection could be expected. A 3D human model is used as the avatar of the presenter. It presents only the factors for assessing the quality of presentations without disturbing the mood of the presenter in the VR space. This paper presents an experimental study that uses this VR-based reflection system. This experimental study focused on which populations could benefit more from such a system and assessed the impact of the factors (avatar or other parts in HMD-based VR) on the reflection effect.  
The paper was organized as follows--in the next section, related work on VR public speaking training systems and the individual differences in training results are presented. In Section 3, the main concepts that lead to the design of the system are described. The system itself is detailed in Section 4, and the experiment is described in Section 5, in which 24 graduate students were trained to observe their own presentations while they were using the system. The results are presented and discussed in Sections 6 and 7.