prevention functions that should drive design and management standards. Concurrent with Jeffery's largely theoretical work was Oscar Newman and George Rand's empirical study of the crime-environment connection conducted in the early 1970s. As an architect, Newman placed emphasis on the specific design features, an emphasis missing in Jeffery's work. Newman's "Defensible Space – Crime Prevention through Urban Design (1972) includes extensive discussion of crime related to the physical form of housing based on crime data analysis from New York City public housing. "Defensible Space" changed the nature of the crime prevention and environmental design field and within two years of its publication substantial federal funding was made available to demonstrate and study defensible space concepts. As established by Newman, defensible space must contain two components. First, defensible space should allow people to see and be seen continuously. Ultimately, this diminishes residents' fear because they know that a potential offender can easily be observed, identified, and consequently, apprehended. Second, people must be willing to intervene or report crime when it occurs. By increasing the sense of security in settings where people live and work, it encourages people to take control of the areas and assume a role of ownership. When people feel safe in their neighborhood they are more likely to interact with one another and intervene when crime occurs. These remain central to most implementations of CPTED . In 1977, Jeffery's second edition of Crime Prevention Through Environmental Design expanded his theoretical approach to embrace a more complex model of behavior in which variable physical environments, offender behavior as individuals and behavior of individual members of the general public have reciprocal influences on one another. This laid the foundation for Jeffery to develop a behavioral model aimed at predicting the effects of modifying both the external environment and the internal environment of individual offenders. 1980s By the 1980s, the defensible space prescriptions of the 1970s were determined to have mixed effectiveness. They worked best in residential settings, especially in settings where the residents were relatively free to respond to cues to increase social interaction. Defensible space design tools were observed to be marginally effective in institutional and commercial settings. As a result, Newman and others moved to improve defensible space, adding CPTED based features. They also deemphasised less effective aspects of defensible space. Contributions to the advance of CPTED in the 1980s included: The "broken windows" theory, put forth by