## 2 Network Analysis for UX Assessment  
Evaluating product or service experiences is difficult because of fundamental differences among individuals. People have different backgrounds and gain different experiences in various contexts, and tradition, common sense, and ideology have direct or indirect control over actions and thoughts with respect to all actions (e.g., purchase of products or services) [17]. Determining which values are important and how important they are is the key to quantifying the UX of products or services.  
Although there are various methods for evaluating UX, there is no single method that is suitable for diverse products or services. Usually, well-defined hierarchical structures delivered by professionals have been used in the field of human-computer interaction, for instance, performance and image/impression dimensions [2]; ten usability heuristics [18]; effectiveness, efficiency, and satisfaction [1]; and usability, affect, and user value [8]. For the products or services which had not been considered in the development of the hierarchical structures, these measures do not capture some aspect of UX. For example, to some people, performance dimensions are not important when they choose clothes, while the performance dimensions such as reaction times or errors [19; 20] are still important across medical devices.  
This study investigates the ability of network analysis to build a value structure, as an equipment of quantifying user value. The structure is composed of values that can be used to evaluate the UX of a product or service and may vary over contexts. Thus, a UX assessment method should efficiently and effectively capture unsettled evaluation dimensions such as the value structure, in contrast to traditional evaluation methods that settle evaluation dimensions, such as [PERSON]'s heuristics (e.g., visibility of system status, consistency and standards, and error prevention) [18]. Network analysis can be a potential alternative to these methods.  
Network analysis has been widely employed to determine the relationships between social entities such as humans and other social animals. Since [21] first adopted a network approach, many researchers in the field of sociology have used so-called social network analysis [22; 23; 24; 25]. Network analysis has been adopted in other areas including molecular network and communication [26; 27]. In these cases, nodes in network structures can represent various targets: one study defined nodes as biomolecular species, and the other defined nodes as web pages. This adaptability allows network analysis to be applied to various fields.  
The most relevant network studies to UX assessment is semantic network analysis. With prominent propositions that memory structure connects individual items [28] and activation of a node in the network spreads to another node [29], efforts on semantic network analysis have been carried out in the field of psychology, information science, and computer science. Recently, studies about semantic network analyses focused on comparing products, services, or brandings [30; 31] and improving the reliability of an application [32; 33]. However, few studies have existed to apply semantic network analysis to UX assessment.