摘要:This paper reviews the research on how one passes through an aperture between non-human objects or between humans. In particular, we discuss what it has so far elucidated and what should be investigated in the future. The previous studies have focused on aperture passability between non-human physical objects and revealed the relationship between how people actually pass through an aperture and how they perceive themselves in relation to environmental characteristics by looking at how people judge passability of an aperture (often formalized as π -number). Most researchers have attended to the factors associated with an actor passing an aperture and/or non-human objects constituting an aperture, but few have examined how one passes an aperture comprised of humans. This may be because it is difficult to experimentally control underlying factors such as conversations and/or physical/social interactions between humans, symmetry of an aperture due to different shapes of the human body, anisotropic shape of personal space, eye gaze, and/or eye contact. Despite these difficulties, we consider it important to study how people pass an aperture between humans, because, first and foremost, that is what we do in everyday life, and, secondly, the outcome will illuminate how people consider socio-cultural factors, personal space,opportunities of actions (i.e., affordances) by ourselves and others. Possible solutions to the difficulties may include use of virtual reality technologies, computer simulation to control the experimental settings to guarantee reproducibility. There are the pros and cons with these methods to discuss, because, depending on how they are employed, they may possibly spoil the very social and interactive (improvisational) nature of the phenomenon under discussion.