# Virtual Reality as a Reflection Technique for Public Speaking Training
## 2 Related Work  
At present, there are systems that use information technologies (IT), such as VR, to enhance people's public speaking skills. For the sake of simplicity and reality, public speaking training that uses VR has been proposed for decades [12], and several companies have introduced practical VR training software to the market in recent years [3; 4]. Many recent studies have featured implementations of an automatic evaluation system, where users received assessment results. For example, [PERSON] et al. developed a framework that provides feedback to users by combining the automatic nonverbal assessment in the presentation video with the system and human subjective feedback through crowdsourcing [13]. [PERSON] et al. propose a tool called Presentation Trainer to provide feedback on nonverbal communication aspects, which identified 131 nonverbal communication practices that affect the quality of a presentation [14], and they also extended it in VR [15]. [PERSON] et al. proposed an algorithm to estimate the public speaking competence rubric (PSCR) [16] score, which involves using body movements, facial expressions and linguistic information [17]. [PERSON] et al. proposed a method for presenting simple icon-based feedback to users who speak in front of an audience while wearing smart glasses [18]. [PERSON] et al. proposed a VR public speaking training system that is based on the idea of placing a VR character as an audience member, and the VR character can react in the same manner as real audience members [19]. We categorize public speaking training with two axes--information provision timing and information acquisition methods, as shown in Figure 1. Information acquisition timing includes learning the information before, during and after the presentation, while the methods of information acquisition are divided into feedback-based and reflection-based (self-awareness-based) methods. In the former type, a trainee is taught by others or by the system what aspects he or she should improve (and how to improve them) [19]. In contrast, in the latter type, the speakers discover what aspects they should improve (and how to improve them) by themselves based on the provided information. Such reflection-basedmethods could help with some part of a speech which does not have any accurate rules and to find a unique style for public speaking. This is also what this study was focused on. Reflection is a cognitive process for learning from experiences [20; 21]. The most common method of reflection is to record the audio of a presentation and then have the presenter listen to it afterwards. This is known to be effective for reflecting upon the prosodic information, involving the volume, inflection, timing and fluency of the voice as well as the content. Video recording has been proven to be a useful pedagogical tool for public speaking courses, as well as more general training [9]. Both verbal and nonverbal elements of the speaking performance can be recorded for subsequent review and analysis. Through video recording, speakers can recall their actual speeches and improve their skill acquisition methods, speech content, and objective test performance [7]. In addition, it can reduce the speakers' anxieties and perceived social costs, and increases the positive appraisals of the performance [8]. However, according to [10], people with public speaking anxiety are more likely to avoid watching their video recording because they are not willing to confirm their negative performance. These presenters tend to be more aware of their personal appearance than their performance, which would affect their self-assessment and reflection. To mitigate the disadvantages, while retaining the advantages, of video reflection, a system which applies VR with a 3D avatar and records a presenter's motion together with an HMD based on the following two ideas was proposed in this study.