# Design Principles of a Mixed-Reality Shopping Assistant System in Omnichannel Retail
## 7 Description of the Design Principles  
We analyzed users' suggestions and feedback reported in the previous section. Consequently, these were combined with the original requirements and design features of the MR shopping assistant. As a result, seven design principles are proposed that can help develop MR-based shopping assistant systems in the future. 1. Rigor: As mentioned in Section 4.1, product recognition offers users a certain amount of accuracy. This makes the system rigorous by detecting the correct product of interest as compared to the manual entry by the user [57]. This feature was received well by the users, and no major suggestions were identified. Although users mentioned the sensitivity of interaction, this can be optimized in the future with advancements in image/product recognition technology. The current state-of-the-art tool, Vuforia SDK, is used by developers to deploy product recognition in the system and provide a rigorous application that can help enhance a user's customer experience. Hence, MR-based shopping assistants should provide a rigorous system that minimizes error and consequently enhances the users' shopping experience. 2. Informativeness: Prior studies in e-commerce suggest that customers seek information in shopping assistant platforms to make buying decisions [59]. This is one of the most important features that has been used in many different channels of e-commerce. With the advancement of the Internet and other information sources, customers seek more diverse information. In addition to traditional text-based information in physical and web-based retail platforms that communicate the price, brand, etc., customers consider information such as reviews from fellow customers, online videos, off-shelf availability of the product, and information that is specific to the category of products, such as dietary information for food products. These findings suggest that an MR-based shopping assistant system should integrate a diverse set of meta-information elements to help customers make better buying decisions. 3. Tangibility: An MR-based shopping assistant system aims to integrate different touchpoints in retail. Tangibility is one of the features that MR technology can leverage in the retail sector. Digital platforms based on the web or smartphones lack in conveying tangible information. An MR system can overcome this limitation by deploying 3D objects in physical environments that are rendered according to their physical properties. The results of this study reflect that customers seek features such as a 360\({}^{\circ}\) view, 3D models of the product, etc., to better understand the product. 4. Summary: This principle correlates with the crisis of immediacy [67], where customers seek assistance in real time and as quickly as possible. Many customers have hinted towards faster options to seek all the necessary information in a concise manner, e.g., a summarized rating of stars, a comparison between different products, etc. This enables making faster buying decisions for products that are more utilitarian in nature and do not need a large amount of information. This can also apply to products that do not need to be used to be judged on their quality [7]. 5. Comparability: The retail market offers a huge stock of products; therefore, customers seek to compare products to make better buying decisions. Hence, a shopping assistant system should be able to provide these options to help make informed decisions. Examples can be comparisons between items in terms of color, price, and reviews, or offer similar products in terms of recommendations. 6. Flexibility: The results show that users seek flexibility or customization options in their shopping experience and the shopping assistant interface. This includes changing the language, customizable color schemes, and the option to resize windows. Customers also expressed the importance of having options to design their shopping journey, such as shopping offline or choosing different delivery options.