Keywords: Local assembly minutes, Visualization, Information retrieval
This paper illustrates a web-based system for visualizing prefectural assembly minutes in Japan. It was public-released in February 2018. Although many local governments in Japan provide public access to political documents, researchers and scientists cannot take full advantage of them because they consist only of raw text. Therefore, there is a need for these to be converted into panel data and to visualize differences by region or over time. For ordinary citizens, visualizing differences between the topics discussed by assembly members can be useful in assessing their characteristics. The proposed system aims to provide a complete solution that meets all of these requirements. The system has five main functions: i) full-text search for political documents, ii) showing keywords in context, iii) map and time-series visualization, iv) cross-tabulation, and v) political keyword extraction. Although three existing systems offer some of these functions, the proposed system integrates all the five necessary functions and provides a complete solution that meets all of the requirements.