I have made innovative contributions to research on individual accessibility, environmental health, human mobility, neighborhood effects, critical and qualitative GIS, and geographic information science (GIScience). Some of my most significant contributions are described as follows (with links to the most representative publications in the respective areas):
(1) Space-time accessibility measuresMy work in this area began in the late 1990s. It sought to shed new light on the gender differences in the access to jobs opportunities and the predominance of men and women in different occupations in local labor markets (i.e., gendered occupational segregation). The results obtained from the space-time analysis of accessibility and innovative geocomputation and 3D geovisualization methods I developed in this research have fundamentally changed our understanding of the methods used to study access to jobs and health care. First, all conventional measures of accessibility suffer from an inherent gender bias that has hitherto unnoticed because they ignore the spatiotemporal complexities of people's daily activities and trips and the role of space-time constraints. Second, space-time measures are capable of capturing inter-personal differences in individual accessibility, while conventional measures are not able to do so since the spatial patterns of accessibility they generate basically mimic the spatial patterns of jobs or urban opportunities. Third, the place accessibility of a person's residential location does not automatically reflect her/his personal accessibility. These results have profound methodological implications for the future study of access to jobs and urban opportunities. They show that the conceptual basis and operational form of an accessibility measure dictate what it is capable of reflecting.
(2) ICT, mobile communications, and geographic analysis in the 21st centuryI have contributed important reflections on the implications of information and communication technologies (ICT) for geographic analysis in the 21st century. I have questioned the suitability of conventional urban models and proximity-based methods for understanding urban travel and urban structure. I have proposed that the study of urban travel now needs new conceptualizations and methodologies because ICT use has fundamentally changed the ways in which we use urban space and interact. The important ideas I put forward include: (a) the role of distance has become much more complicated in contemporary society; (b) urban and spatial interaction models formulated in the mid-20th century are no longer adequate now; (c) ICT use does not necessarily improve gender equality in the household and in society at large; (d) time is an integral elements in understanding contemporary urban structure and travel; and (e) new concepts and methods are sorely needed to advance our understanding of urban form, urban travel, and spatial interaction in the age of mobile communications.
(3) Critical and feminist GISThrough my work on feminist visualization, affective geospatial technologies, and qualitative GIS in the 2000s, I have made innovative contributions that moved geographers beyond the impasse and tension between GIScience and critical geographies. Based on my several projects, including a study of the post-9/11 anti-Muslim hate violence against the Muslim women in Columbus, Ohio, I illustrated how alternative GIS practices based on feminist and critical theory might look like. My work has contributed significantly to the advancement of critical GIS and to the nascent subfield of the geographies of emotion and affect. My articles in this area have also helped deconstruct the binary understanding of geographic method (e.g., GIS methods can be both quantitative and qualitative at the same time), as well as the importance of the critical agency of GIS users or researchers in s haping the concrete practice or use of GIS in geographic research.
(4) Geo-narrativeI developed a GIS-based approach to narrative analysis that contributed to advancing qualitative methodologies in significant ways. Such approach (called Geo-narrative) was developed for the analysis of narrative materials such as oral histories, life histories, and biographies. The method involves three-dimensional narrative analysis and the composition of time-geographic visual narratives. It was the first attempt that developed and incorporated qualitative data analysis capabilities within a GIS. My work on Geo-narrative not only contributed to advancing qualitative methodologies, it has also received considerable attention from health researchers and has inspired many recent projects, many of which are funded by NIH. For instance, Geo-narrative has been used in a research project that examine the health risks of female sex workers in the US-Mexico border (see the Geo-Narrative webpage for more information).
(5) Hybrid geographiesI have advanced several ideas that changed how geographers think about the disciplinary dynamics of geography, geographic method, and several fundamental divides in the discipline. For instance, in my 2004 Annals of the AAG article (Beyond Difference), I explored the notion of hybridity and its potential for redressing the polarizing tendency in the discipline. I argued that hybrid geographies would help avoid the tendency of thinking geographic practices in purified and binarized categories and perpetuating the social-cultural/spatial-analytical rift. Hybrid practices include using quantitative or GIS methods to address issues informed by critical geographies, crossing the boundary between geospatial technologies (GIS and GPS) and a qualitative understanding of the lived experiences of individuals in various cultural contexts through mixed methods approaches, and integrating critical social theory and spatial analytical methods.
(6) The uncertain geographic context problem (UGCoP)In two 2012 articles, I first articulated the uncertain geographic context problem (UGCoP), which refers to the problem that findings about the effects of area-based attributes (e.g., land-use mix) on individual behaviors or outcomes (e.g., physical activity) could be affected by how contextual units or neighborhoods are geographically delineated. The UGCoP is now an important concept in social science, health, and geographic research. In much health geography research, spatial contexts have been depicted as fixed geographic entities (neighborhoods or buffer zones), whereas I proposed to conceptualize them as dynamic and contingent as a result of people's daily mobility. By dynamically linking individual mobility and exposure to real-time contexts using geospatial and sensing technologies (e.g., GPS and mobile sensors) through the perspective of the UGCoP, my work in this area has inspired much new research in health geography, public health, urban studies, and sociology (e.g., on a wide range of topics including individual exposure to air pollution, noise, traffic congestion, green spaces, social environments, racial/ethnic segregation, and transission risk of infectious disease). Many papers published subsequently provide strong evidence on the importance of the UGCoP (see the UGCoP webpage for more information).
(7) Dynamic conceptualizations of segregation and environmental exposureMany notions in geographic and social science research still tend to be conceptualized largely in static spatial terms, ignoring how our understanding of the issues we study can be greatly enriched through the lenses of time and human mobility. Past research also tends to ignore various facets of time (e.g., rhythm, duration, and subjective experiences of time) that shape people's spatiotemporal experiences of marginalization, discrimination, and social isolation. In my 2013 article in the Annals of the AAG (Beyond Space), I argue that three geographic notions will benefit enormously from integrating time as a critical dimension: racial/ethnic segregation, environmental exposure, and accessibility. Because these three notions together address a wide range of social issues (e.g., social inequality, social isolation, environmental justice, environmental health, and access to social services and health care facilities), I indicate that expanding our analytical focus beyond space to include time and human mobility will considerably enrich our understanding of how individuals of different social groups experience racial/ethnic segregation, exposure to environmental influences, and access to social facilities. I suggest that exploring the analytical links among segregation, environmental exposure, and accessibility through some hybrid constructs seem a fruitful direction for the future development of temporally integrated geographies.
(8) Algorithmic geographiesIn a 2016 article in the Annals of the AAG (Algorithmic Geographies), I first articulated the idea that in the era of big data, the production of geographic knowledge has become more dependent on computerized algorithms than before. I argued that the advent of big data has significantly increased the role of algorithms in mediating the geographic knowledge production process. This increased importance of algorithmic mediation introduces much more uncertainty to the geographic knowledge generated when compared to traditional modes of geographic inquiry. I alerted researchers about the risk of ignoring the potentially significant influence of algorithms on research results and the possibility that knowledge about the world generated with big data may be more an artifact of the algorithms used than the data itself. I called this new kind of geographic inquiry algorithm-driven geographies (or algorithmic geographies). I highlighted the need for geographers to remain attentive to the omissions, exclusions, and marginalizing power of big data. The paper is an important contribution to the emerging subfield of digital geographies.
(9) The neighborhood effect averaging problem (NEAP)In 2018, I published two other articles that extend the UCGoP argument, one on the neighborhood effect averaging problem (NEAP) and the other on the limitations of conventional notions of the neighborhood effect. Specifically, the NEAP refers to the problem that individual mobility-based exposures tend towards the mean level of the participants or population of a study area when compared to their residence-based exposures. It may lead to erroneous assessments in the study of mobility-dependent exposures (e.g., air/noise pollution) because people's daily mobility may amplify or attenuate the exposures they experienced in their residential neighborhoods. This means that using residence-based neighborhoods to estimate individual exposures to and the health impact of environmental factors may overestimate the statistical significance and effect size of the neighborhood effect. I have subsequently published 5 co-authored papers that provide strong evidence on the existence the NEAP and its policy implications (e.g., increasing the mobility of those who live in disadvantaged neighborhoods through better, safer, and more reliable public transit can be helpful for improving their health outcomes) (see the NEAP webpage for more information).
Last Updated on April 24, 2021.