# Conceptual Design of an Extended Reality Exercise Game for the Elderly
## 3 VRrowing Conceptual Design
### Design Principles  
As an exercise game for the elderly, we considered design principles both in relation to exercise games and human-computer interaction for seniors in our design process. Based on the work by [PERSON] [56], [PERSON] and [PERSON] [57], and [PERSON] [58], [PERSON] et al. [59] distilled a list of design principles in daily fitness games, which includes the core mechanics, representation, micro goals, marginal challenge, free play, social play, and fair play. These design principles are as follows. The core mechanism is a set of fundamental interactions, which are frequently repeated activities by users during use, and are also the key to influencing the formation of physical habits. In our VR game, the core mechanism is rowing. A suitable representation could provide context for the game, which balances the aesthetic and narrative, being concise without losing meaning, driving player interaction and immersion in the game. Micro goals are designed to push players and help them measure their game progress; the short-term micro goals satisfy and attract players to continue use through quantified results and rewards. Moreover, the marginal challenge is to challenge the edge of the player's ability to enrich the game experience and stimulate fun and satisfaction. Free play means reducing the interaction limitation and giving space for players to play at their own pace. Finally, social play and fair play are principles relevant to multi-user and teamwork. In an exercise game design, social relations should be considered both internally (roles from the game, such as seeker and the hiders in a hide and seek game) and externally (roles from outside, such as rivalries and friendships). The internal roles could help create new external relationships and maintain such relationships through communication tools in the game. Fair play, as the name suggests, allows all players to have an equal chance of winning. This first requires that the core mechanics and game rules are fair, second that players of similar skill levels are matched, and third that it provides a temporary advantage to backward players to regain competitiveness. [PERSON] et al. thought the main reason for the potential \"technophobia\" of the elderly was that hardware and software design (particular interface design) neglected their particular needs and did not suit them [9]. Their work tried to design the right interaction method for machines and seniors' communication to let them access the techniques. They summarised the factors that hinder the elderly accessibility and acceptance of new techniques, centred on them, and pointed out the human-computer interaction principles for elderly requirements, which include the consideration of changes related to ageing that cover motor, cognitive, and perceptual perspectives, acceptance issues, and emotional experience. Usability and acceptability can be affected by changes in perception, movement, and cognition. Ignoring the changes in these aspects of the elderly could lead to dissatisfaction with the product and refusal to use it [9]. Problems could be hard-to-read text, puzzling icons, etc. [60]. [PERSON] et al. agreed that one of the main design taskswas to make the technology \"familiar\" to the user, thus removing the main two barriers in the process of accepting the technology (lack of perception of technological superiority, negative expected for return on investment when using products) [9]. Besides usability and acceptability, aesthetics, emotion, pleasure, and affection should be considered in the design as well. Especially in designing a product used at home, one needs to consider the user, objects, and the usage context integrated into a network of interactions and actions. Except for efficiency-oriented principles, the design should be grounded on aesthetics and the artefact, as well as concerning the emotional needs of the home. According to the [PERSON] et al. MDA framework as the design method, this paper analysed and created the conceptual design for the _VRrowing_ prototype.