how one or more parameters produce an effect while other measures are controlled. It is impossible to manipulate real-world settings in a laboratory. Environmental psychology is oriented towards influencing the work of design professionals (architects, engineers, interior designers, urban planners, etc.) and thereby improving the human environment. On a civic scale, efforts toward improving pedestrian landscapes have paid off, to some extent, from the involvement of figures like Jane Jacobs and Copenhagen's Jan Gehl. One prime figure here is the late writer and researcher William H. Whyte. His still-refreshing and perceptive "City", based on his accumulated observations of skilled Manhattan pedestrians, provides steps and patterns of use in urban plazas. The role and impact of architecture on human behavior is debated within the architectural profession. Views range from: supposing that people will adapt to new architectures and city forms; believing that architects cannot predict the impact of buildings on humans and therefore should base decisions on other factors; to those who undertake detailed precedent studies of local building types and how they are used by that society. Environmental psychology has conquered the whole architectural genre which is concerned with retail stores and any other commercial venues that have the power to manipulate the mood and behavior of customers (e.g. stadiums, casinos, malls, and now airports). From Philip Kotler's landmark paper on Atmospherics and Alan Hirsch's "Effects of Ambient Odors on Slot-Machine Usage in a Las Vegas Casino", through the creation and management of the Gruen transfer, retail relies heavily on psychology, original research, focus groups, and direct observation. One of William Whyte's students, Paco Underhill, makes a living as a "shopping anthropologist". Most of this advanced research remains a trade secret and proprietary. Environmental psychology is consulted thoroughly when discussing future city design. Eco-cities and eco-towns have been studied to determine the societal benefits of creating more sustainable and ecological designs. Eco-cities allow for humans to live in synch with nature and develop sustainable living techniques. The development of eco-cities requires knowledge in the interactions between "environmental, economic, political, and socio-cultural factors based on ecological principles". Organizations Project for Public Spaces (PPS) is a nonprofit organization that works to improve public spaces, particularly parks, civic centers, public markets, downtowns, and campuses. The staff of PPS is made up of individuals trained in environmental design, architecture, urban planning, urban geography, urban design, environmental psychology, landscape architecture, arts administration and information management.