Abstract: The office research in environmental psychology that was inspired by the office experiments of Allen and his colleagues in 1970, and undertaken since the 1980s, deemed privacy in the open office setting problematic; however, experiments by Allen showed improvements in privacy. Why was privacy not seen as a problem in Allen's experiments? The office in Allen was not limited to being open; in fact, it also incorporated a free-seating arrangement. Further exploration of Allen's experiments shows that a free-seating arrangement not only enabled employees to move about the office at will but also facilitated the adjustment of their mutual interaction. As a result, it was thought that privacy had actually improved. In other words, extracting an open setting, which is only one aspect of a office space, is insufficient, and thus, free-seating arrangement must also be considered. Doing so increases the possibility of significantly remedying privacy problems.Keywords: office, open plan office, free seating, privacyAllen's Non-territorial Office ExperimentFrom the 1990s into the first decade of the 21st century, the concept of a office space had been adopted by many companies, particularly those aiming to reduce facility costs, increase communication, and facilitate knowledge creation (Becker, 1990; Becker & Steele, 1995; Elsbach & Bechky, 2007; Elsbach & Pratt, 2007; Zelinsky, 1998).Thomas J. Allen, well-known for his research on communication in R&D organizations (Kuwashima, 2012), coined the term office. His proposed concepts of gatekeeper and NIH syndrome continue to be widely researched (e.g., Takahashi & Inamizu, 2012).From June 1970 to April 1971, Allen and Gerstberger (1973)1 performed an experiment that included changing the office layout of a large company's production engineering department. The production engineering department had 10-20 employees, whose daily work involved communicating with various peers to find solutions to new problems. Prior to the experiment, the office of the production engineering department had been divided into separate, traditional private rooms occupied by one or two employees. However, during the experiment, office walls were removed and the existing seating arrangement was replaced with a more communal setting, changing the office layout to non-territorial one.Allen and his colleagues conducted surveys two months prior to the change in layout (June 1970) and again eight months after the change (April 1971). A result, although not statistically significant, showed the tendency for improvement in the items for privacy. Due to this finding, Allen reported an improved sense of privacy among employees that was attributed to the change in the office layout.Prior to the experiment, Allen feared that the subjects would claim their own territories and occupy specific areas. However, contrary to Allen's apprehension, the survey on seating positions showed that the employees frequently moved around throughout the day and almost none of the employees claimed territory by continuing to occupy a specific space.The ratio of employees that were actually in the office (in-office ratio) was calculated with the median at 62.5% and almost never exceeding 80%.An increase was also seen in the amount of communication and in the number of communication partners. In addition, the degree of satisfaction regarding the communication also significantly improved. Although none of the results showed a significant improvement in the overall performance of the department, Allen conjectured, although slightly optimistic, that the resultant active communication would increase the department's performance in the future.Definition of PrivacyThe office proposed by Allen proved to be ahead of its time in Europe and America, where traditional private offices were the norm. …