## 2 Theoretical Background
### Related Research  
The library is the lifelong learning field that connects the local learning setting with the global resources of information and knowledge in the digital era. The library offers education as to how to search and use this information and ensure the quality of information service. Thus, the library can be said to provide information qualifying as an important prerequisite for lifelong learning.  
Moreover, the library holds a large amount of data regarding its users, the users' characteristics, their information needs and information use, which can be of assistance to the library for better managing their resources and services. Library data visualizations could prove a useful tool when it comes to enhancing the decision-making process, and the directors/administration could make more successful operational choices [18].  
[PERSON] assumes that the function of library education is not only to provide information literacy training, but also to face the challenge of data-intensive research services in the era of Big Data. The quality of data provision, data citation, and data literacy issues are critical to academic university library services. To provide these data services, innovative technologies and professionals are required [19]. To meet the requirements of high-quality data services, the library must innovate and continuously develop data visualization and information services to meet the learning requirements of their readers and improve overall information service quality.  
[PERSON] [20] proposed a conceptual framework that presents the information service issue of library innovation that is not based on empirical research, although it has not yet been tested in practice. However, [PERSON] believed that it was a valuable framework for designing and implementing innovative services in libraries. The purpose of [PERSON]'s research was to identify the data sources of innovation in library information services and point out how they can be used to improve the overall information service quality.  
It is usually difficult for the library to provide management staff and users with an efficient and easy-to-understand way of explaining the meaning of such data. According to [PERSON] et al. [21], information visualization is the use of computer-supported, interactive, visual representations of abstract data to amplify cognition. Information visualization allows users to extract data from large databases in an efficient and effective way. Many scientists' data propose that information visualizations can be regarded as a solution for this problem [18].  
The advantage of visualizing data is that the meaning of information is more intuitive through the presentation of data sets. Computer graphics, combined with tags and numerical parameters (such as color, distance, and size), can make information services clearer and more user-friendly. The research framework proposed by [PERSON] and [PERSON] [18] proposes a way to visualize future experiential service innovation, considering how to integrate realism into design methods.  
Based on the above-mentioned related research on the data visualization of libraries, it can be found that most of these only provided implementable conceptual frameworks. Therefore, this research will use specialized IT skills such as interactive technology, the Wi-Fi system, and databases to optimize the data visualization of library information services, and we provide a quantifiable and verifiable theoretical framework that meets the usability principles of information systems.