## 4 Findings and Discussion
### Research Gaps  
We identified the research gaps of virtual commerce research from these perspectives: (1) dominant design artifacts (Table 8) and boundary factors (Table 7) covered in the included papers, (2) characteristics of design-factor mappings (Table 9), (3) promising design artifacts or boundary factors that were ignored, and (4) the latest trends in ICT related to virtual commerce. In the end, the following research gaps were found. First, the design-factor mapping is largely biased. Figure 10 plotted the occurrence of each boundary factor in behavior papers (tallied from Table 7), design artifacts (tallied from Table 9), and design papers (tallied from both Tables 8 and 9). At one end, 14 design artifacts (53%) and 30 design studies (81%) can be categorized into improving consumer's perceived ease of use. Furthermore, eight design artifacts (30%) and 19 design studies (51%) can be categorized into improving consumer's perceived usability. As perceived system ease of use and usability (or usefulness) are two notable factors of the TAM, it can \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Requirement** & **Description** & **Related Artifact Category** \\ \hline Forms of immersive technology & The choice of immersive technology for an application, e.g., AR/VR/VW & AR \\ \hline Interface & Appearance and function of a user interface for different user groups, e.g., client interface for consumer & Client design \\ \hline Performance & Efficiency of given tasks, e.g., customizing product presentation and the appearance of a virtual shopping environment & Customization \\ \hline Intelligence & Provision of intelligent tools to automate certain tasks, e.g., software agent for various retailing tasks & Software agent \\ \hline Function & The special purposes of an application, e.g., reputation enhancing mechanism & Function design \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Design requirements and related design artifact categories. be concluded that most design artifacts (85%) and studies (81%) can improve consumer's acceptance of applying immersive technologies to e-commerce. At the other end, many factors have only been studied insufficiently in design papers, including 3D authenticity, control, vividness, spatial presence, layout, and objective interactivity. Moreover, there is no design paper concerning hedonic value. Second, the biased design-factor mapping hints that there could be more unexplored antecedents of purchase intention. One salient factor is customization/personalization, which has been identified as an important determinant of virtual consumption in both game VWs [144] and social VWs [145], as virtual item customization or personalization can enhance an item's hedonic and social value by showing the player's uniqueness [146]. However, this factor has not been covered in the behavioral studies of e-commerce, especially for online retailing. Even so, some designs have already tried to elicit the value of object [132] or environment [137] customization or shopping experience personalization [140, 138, 142, 46, 139, 140], leading to another gap between behavioral and design studies. Third, variety is absent in the design and factor enhancement related to AR. Most AR design solutions can only improve consumer's perceived ease of use (refer to Table 9) and only one can improve usability [117]. Whether AR can be utilized to enhance other factors has yet to be explored, which is an evident and important gap. From the behavior papers, though five design papers are related to enhancing 3D information quality, they only achieved it through direct product information presentation implemented by AR, while VR-based product presentation has not been discovered within the scope of this paper. Fourth, MR is seldom utilized in the reviewed papers. In the reviewed papers, AR is sufficient for product display and interaction, thus MR is not needed for complex virtual scenes rendering or virtual object interaction.