could see the blackboard and his "grades improved markedly". Sommer devoted a chapter to the effect of classroom structure on learning in his book Personal Space, and also wrote many journal articles on the topic. Though the 1960s and 70s were a time of innovation in educational curricula, teaching methods, and classrooms, there was not much thought given to the physical environment of the classroom and how it might affect learning. Sommer introduced two important terms in his book Tight Spaces: Hard Architecture and How to Humanize It. First, the "open classroom", which he described as being a "more informally arranged and less rigidly structured space", and "open education", a loosening of the current social hierarchy in education where teachers are strictly the sources of knowledge and students only learners. Sommer stated that though the addition of "open classrooms" cannot increase student participation without there also being an environment of "open education", no shift in hierarchy is likely without a change in the construction or arrangement of the classroom.The Soft Classroom is an article written by Sommer and Olsen describing a study they conducted on the impact of classroom design on learning. It described the difference in student participation observed in two differently arranged classrooms. Prison Architecture Robert worked on a federal task force consulting for prisons, he studied their built environment and the relation to psychology. His aim was to apply architectural strategies he had used in mental health facilities to the prison setting. Robert's primary concern throughout his research was whether ‘hard architecture’ instills any sort of reform on the individual, or whether it merely perpetuates the idea of punishment. Tight Spaces: Hard Architecture and How to Humanize It, Author: Robert Sommer, talks about his observations into the soulless architecture of these institutions, and the dehumanizing nature of a prison. Robert faced a difficulty in obtaining reliable data while interviewing in prisons. In one institution he was not allowed to talk to the guards, and was told that interviewing prisoners would violate their privacy. While in another prison, he was barred from interviewing the guards themselves. Street Art Sommer's book Street Art (1975) discussed "the urban community mural in the U.S.A." The community mural is created by artists in collaboration with the local community so the art reflects the local culture. "Some of the chapter topics are: The New Mural Movement; definitions of 'street art' forms; the politics