Core Viewpoint - The article discusses the extensive research conducted by Professor Jin Shan from Hainan University on the Japanese occupation of Hainan Island during World War II, highlighting the importance of historical documentation and field investigations in understanding this period [6][10]. Group 1: Research Background - Jin Shan has been researching the Japanese occupation of Hainan since 2006, discovering a significant lack of local resources but finding ample documentation in Japan due to extensive studies conducted during the occupation [6][7]. - His research has led to the accumulation of over 30 million words of textual materials, photographs, and labor lists, which he meticulously organizes and translates [7][8]. Group 2: Methodology - Jin emphasizes the necessity of combining historical documents with field investigations to validate findings, citing examples of Japanese authors who conducted on-site research during the occupation [8]. - He undertook a three-year effort to translate a significant historical document, demonstrating the importance of thorough fieldwork to ensure accurate translations [8]. Group 3: Ongoing Efforts - Jin continues to travel to Japan annually to gather new materials, often spending extended periods in libraries and archives to maximize his research output [6][9]. - He expresses urgency in his work, noting the loss of potential informants over time, which drives his commitment to document and preserve this historical knowledge [9]. Group 4: Purpose of Research - The research aims not only to collect evidence of Japanese war crimes but also to provide future generations with a comprehensive understanding of Hainan's social conditions during the war [10].

Core Viewpoint - The article highlights the dedication of Professor Zhang Xingji from Hainan Normal University in researching the historical crimes committed by the Japanese military during their occupation of Hainan Island, emphasizing the challenges faced due to a lack of available resources and the importance of rigorous verification of historical data [4][5][8]. Research Challenges and Methodology - Since the 1990s, Zhang has been engaged in the study of Japanese military actions in Hainan, particularly focusing on economic exploitation, facing significant challenges due to the scarcity of relevant materials [4]. - Initial research efforts were hindered by a lack of documentation, leading to a cycle of limited scholarly work in this area. Zhang's breakthrough came through a connection with a Japanese friend who provided access to valuable Japanese-language materials [4]. - Zhang emphasizes the necessity of cross-verifying data from different sources, including Japanese and Chinese documents, to ensure accuracy in historical accounts [5]. Field Research and Data Collection - Field research is deemed equally important as document collection. Zhang and his students conducted extensive data collection at provincial archives, including compiling victim lists from Japanese military actions [7]. - As time progresses, the challenge of interviewing survivors increases due to their advancing age and fading memories. Zhang employs strategic questioning to help them recall details from their past [7]. Significant Contributions - Zhang has contributed to major research projects, including a national study on population casualties and property losses during the Anti-Japanese War, which took nearly a decade to complete [7]. - His published works include "Research on the Crimes of Japanese Occupation in Hainan Island" and various translated historical documents, alongside numerous academic papers on Japanese policies during the occupation [8]. - Zhang aims to clarify historical truths through meticulous research, aspiring to elevate the study of Hainan's wartime history and provide lessons for future generations [8].