# Design Principles of a Mixed-Reality Shopping Assistant System in Omnichannel Retail
## 4 System Design
### Requirement Extraction
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Design Feature** & **Purpose** & **Description** \\ \hline Product information & Provides relevant information about the product’s features and characteristics. & Shoppers seek information about their purchases through online and offline channels, which encourages digital applications to provide this information [59]. Product information is one of the critical components for customers’ intentions to use shopping assistants [7]. \\ \hline Reviews (textual and star rating) & Supports decisions by anecdotal comments from fellow shoppers. & Reviews “are viewed as valuable because peers who have no interest in positively biasing the content presented on application, provide the product reviews” [7]. Reviews enable an opportunity for the shopper to evaluate the product based on prior shopper experiences. Consequently, this helps customers in the decision-making phase. \\ \hline Recommendations & Helps to find similar, supplementary, or additional products. & Recommendations provide an opportunity to discover new products [18]. These recommendations can be tailored according to the user’s preferences, providing a personalized shopping experience, and finding preferential products. \\ \hline Videos & Enriches product information with embodied clips about using the product, user instructions, reviews, unboxing, etc. & Video-sharing platforms play a significant role in shaping customer perception and decision-making processes [60]. Previous studies also used videos as metadata for products in retail environments and even for AR retail applications [61]. These have been used in various forms, such as product advertisements and reviews from other customers environments [62; 63]. \\ \hline Availability & Provides information about online or on-shelf stock in the vicinity of the user. & Prior research advocates integrating offline inventory in online media to provide customers a better shopping. \\ \hline The buy button & Enables the completion of the purchase journey on the spot or home delivery. & Conducting the actual purchase is an integral part of digital retail and e-commerce platforms [65; 66]. This is performed due to crises of immelacy [67], where the customer needs to be addressed in real time. Hence, this feature would allow the shopper to add a product to a virtual shopping cart and continue shopping towards the final purchase either digitally or at the POS. \\ \hline Virtual shopping cart & Allows users to add and delete products and review the shopping list before payment. & The cart gives the user a sense of security by introducing a two-step process before payment to make the final purchase decision with more confidence. The shopping cart secures online price promotions, obtaining more information on specific products, organizing shopping items, and entertainment [68]. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Design features for an MR shopping assistant. recognition technology, customers can apply hand gestures to interact with 3D buttons. An NUI interface aims to provide users with experience in a hedonic sense by making it fun, enjoyable, easy, and intuitive to control and interact with the system [48]. The desired NUI interface provides a hedonic experience without compromising the utilitarian aspect of performing the shopping task (i.e., goals). The three requirements are summarized in Table 2.