Seeing Cities Change.

From Simmel, through Lefebvre, Sennett, and Lofland, the visible, and the symbolic, have been central to urban analysis. Cities have always been the most dynamic sites for symbolic competition between the groups who live and work within them. Today diversity is simultaneously increased and concentrated by the contradictions of globalization. As noted by Sassen, both the powerful and the powerless are concentrated in cities and even the most marginalized find ways to claim contested terrains. Urban neighborhood change takes many forms. One of the most common urban scenarios are ethnic and racial transformations produced by migration. Another is the gentrification of once socially marginal areas in which competition today between the most and least powerful has become a global tableau. Ever since Robert Ezra Park and Ernest Burgess published their classic research on Chicago, which described "how" residential neighborhoods follow a distinct ecological pattern, generations of urban practitioners and theoreticians have been arguing about "why" they are spatially distributed. This paper is designed to demonstrate the utility of visual and virtual approaches to the study of ordinary streetscapes to document and analyze how the built environment reflects changing cultural and class identities. It also discusses how these changes relate to issues of local and national identities, and multiculturalism. It is multidisciplinary, cross national, and comparative in order to synthesize some of the most important older and newer theoretical perspectives on interrelated urban phenomena. This paper explores how abstract ideas are visualized in competing spatial practices. [ABSTRACT FROM AUTHOR]