Enhancing trust in virtual reality systems

Introduction

Virtual Reality

Virtual Reality (VR) is a technology that has seen recent increase in interest, both in academia and among the general public, mainly thanks to the decrease in cost and increase in quality (Young, Gaylor, Andrus, & Bodenheimer, 2014). The potential of VR has been known for decades, and this technology is nowadays applied in several fields. VR has been seen as effective in fields including industry (Lawson, Salanitri, & Waterfield, 2016), healthcare (Ma, Jain, & Anderson, 2014), training (Borsci, Lawson, Salanitri, & Jha, 2016) and education (de Faria, Teixeira, Junior, Otoch, & Figueiredo, 2016). Thanks to the aforementioned decrease in cost and increase in quality, the studies on VR systems have increased significantly, and the advantages that VR offers compared to other technologies are now clearer. The improved sense of immersion and the possibility to explore objects and environments not accessible in real life are among the most valuable characteristics in VR technology.

VR in education

Several VR systems have been developed for teaching and learning over the years. Twenty-four years ago, Psotka (1995) highlighted the advantages of VR applied to the educational field. The author stated that the immersive power of VR could pave the way for VR as an effective and widely used system. Since then, important advancements have been put in place in the field of VR, and more systems have been developed. For instance, Kauf- mann, Schmalstieg, and Wagner (2000) developed a system called Con- truct3D to help teach mathematics and geometry. The system, composed of a stereoscopic Head Mounted Display (HMD) and a two-handed 3D control tool, was developed to help the visual representation of geometric shapes and to improve the spatial abilities of children. Odor (2009) developed a 3D system to teach Sign Language. The author stated that the 3D representation and the possibilities of varying speed and position and choosing an avatar can improve the process of learning Sign Language, de Faria et al. (2016) analysed the effectiveness of VR for medical and anatomical education. The authors found that there was a statistically significant improvement in students’ results when learning through VR systems compared to learning by conventional methods. Other than single cases, several literature reviews were performed on the field of VR in education (e.g. Hew & Cheung, 2010; Lee, 2010 Sitzmann, 2011; Vogel et al., 2006). These reviews all found that VR, simulations and games increase the effectiveness of learning. Some negative impact was also found, such as the negative attitude of students on using simulation for learning when left without guidance on how to use the system and the reduced effectiveness when the user is not in control of the system. One of the most complete literature reviews was made by Merchant, Goetz, Cifuentes, Keeney-Kennicutt, and Davis (2014). The analysis focused on Desktop-VR used for K-12 (kindergarten to 12th grade in the U.S. school system) and higher education and included games, Virtual Words and simulations. The authors explored a total of 69 studies and found that various types of VR are effective in improving learning outcomes (Merchant et al., 2014). The results of the analysis found that desktop-VR is a very effective method in teaching and that, in general, games are more effective than simulations and virtual worlds.

Trust in VR

Despite the positive outcomes reported above, in order for VR systems to be used effectively there is an important aspect that has to be taken into consideration: the trustworthiness of the system. Various research has highlighted that the perception of trust influences the interaction between the user and the technology and it can be a turning point in the decision to use (or not) the system. Technologies like e-commerce (Ba, Whinston, & Zhang, 1999; Kim & Peterson, 2017), social networks (Lankton & McKnight, 2011) and automated systems (Muir & Moray, 1996) have been seen to require users’ trust to be effective and actually used at all. However, there is still discussion in the literature on the factors influencing people’s trust in technology and especially the factors influencing trust in VR. Lippert and Michael Swiercz (2005) theorised different types of determinants of trust in technology: organisational, technological and user.

The model of trust created by McKnight et al. (2011) explains that trust in technology is given, in general, by three factors: trust in a specific technology (functionality, reliability and helpfulness), propensity to trust and institution- based trust. While propensity to trust and institution-based trust are more related to personal and organisational characteristics (same as the ‘organisational’ and ‘user’ characteristics described by Lippert & Michael Swiercz, 2005), functionality, reliability' and helpfulness are more related to the technology' characteristics and can, therefore, be improved in the technology' design.

While these models usefully frame our understanding of trust in technology, there is not yet a complete model of factors that could influence trust in VR systems, which may differ from other technologies for their possibility to immerse the user and the different type of interaction involved (e.g. the use of stereoscopic view, the use of seamless interaction devices).

Trust in VR education

In education, the trust people have in the technology they are using is a key factor for the effectiveness of the system. Wang (2014) highlighted how, for instance, e-learning causes more doubts than face-to-face education, because the potential risks of using a technology (e.g. privacy, technology failure) have to be taken into account by students when deciding to study remotely. These risks and doubts cause a higher number of dropouts in e-learning course than in face-to-face courses (Bell & Federman, 2013; Patterson & McFadden, 2009; Tyler-Smith, 2006). Understanding how to increase users’ trust in the VR system they are using could therefore be a key factor for the success of this technology in the educational field.

The model

The literature suggested three main factors influencing trust in VR systems: technology acceptance, usability and presence, which were used to build a model to investigate trust in VR. Key findings from each area follow.

Technology acceptance

Various studies (Gefen, Karahanna, & Straub, 2003; Hernandez-Ortega, 2011; Wu, Zhao, Zhu, Tan, & Zheng, 2011) demonstrated the relationship between technology acceptance and trust. Davis (1985) first theorised the concept of technology acceptance and developed the Technology Acceptance Model (TAM). According to Davis (1985), there are two factors of technology acceptance: perceived usefulness and perceived ease of use. Perceived usefulness is defined as the users’ belief that the technology will improve their performance. Perceived ease of use refers to the effort needed to use the technology (Davis, 1985). Technology acceptance explains 40% of the users’ intention to use the system (Venkatesh & Davis, 2000). Studies in the literature investigate the relationship between technology acceptance and trust. Trust has been related to technology acceptance in online purchasing (Gefen et al., 2003), online gaming (Wu et al., 2011) and e-banking (Suh & Han, 2003). In a meta-analysis, Wu et al. (2011) found that trust is positively correlated with both factors of technology acceptance. Hernandez-Ortega (2011) demonstrated that perceived ease of use is one of the factors influencing trust.

Usability

Usability is extensively studied in human factors and is based on whether technology satisfies users’ needs (Bevan, 2009). Bevan, Kirakowski, Maissel, and Maissel (1991) defined usability as

the ease of use and acceptability of a system or product for a particular class of users carrying out specific tasks in a specific environment; where “ease of use” affects user performance and satisfaction, and “acceptability” affects whether or not the product is used.

(p. 652)

The choice of usability was made following studies in the literature on the relationship between usability and trust (Bevan, 2009; Roy et al., 2001) and the fact that usability was included as a factor of trust in some previous studies (e.g. Lippert & Michael Swiercz, 2005).

Presence

One of the best known definitions of presence is the sensation of being in a place, while situated in another (Witmer & Singer, 1998). Therefore, if a VR system induces enough presence, the users will develop the belief that they actually are present in the virtual environment instead of the ‘real’ one. Expansion of the definition of presence was given by Slater (2009). The author argued that presence is composed of two orthogonal concepts: Place Illusion (PI) and Plausibility illusion (PSI). PI corresponds to the sensation of being there. That is the classic definition. PSI is the illusion that what it is happening in the virtual world, is actually happening.

The choice of presence as a potential factor influencing trust in VR was due to the importance this concept has in the VR field; it is one of the most studied and important factors in VR (Sanchez-Vives & Slater, 2005; Slater & Wilbur, 1997; Witmer & Singer, 1998).