Supporting Range Queries on Web Data Using k-Nearest Neighbor Search Wan D. Bae 1 , Shayma Alkobaisi 1 , Seon Ho Kim 1 , Sada Narayanappa 1 , and Cyrus Shahabi 2,⋆ 1 Department of Computer Science, University of Denver, USA {wbae,salkobai,seonkim,snarayan}@cs.du.edu 2 Department of Computer Science, University of Southern California, USA shahabi@usc.edu Abstract. A large volume of geospatial data is available on the web through various forms of applications. However, access to these data is limited by certain types of queries due to restrictive web interfaces. A typical scenario is the existence of numerous business web sites that pro- vide the address of their branch locations through a limited “nearest location” web interface. For example, a chain restaurant’s web site such as McDonalds can be queried to find some of the closest locations of its branches to the user’s home address. However, even though the site has the location data of all restaurants in, for example, the state of California, the provided web interface makes it very difficult to retrieve this data set. We conceptualize this problem as a more general problem of run- ning spatial range queries by utilizing only k-Nearest Neighbor (k-NN) queries. Subsequently, we propose two algorithms to cover the rectan- gular spatial range query by minimizing the number of k-NN queries as possible. Finally, we evaluate the efficiency of our algorithms through empirical experiments. 1 Introduction Due to the recent advances in geospatial data acquisition and the emergence of diverse web applications, a large amount of geospatial data have become available on the web. For example, numerous businesses release the locations of their branches on the web. The web sites of government organizations such as the US Postal Office provide the list of their offices close to one’s residence. Various non-profit organizations also publicly post a large amount of geospatial data for different purposes. ⋆ The author’s work is supported in part by the National Science Foundation un- der award numbers IIS-0324955 (ITR), EEC-9529152 (IMSC ERC) and IIS-0238560 (PECASE) and in part by unrestricted cash gifts from Microsoft and Google. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. J.M. Ware and G.E. Taylor (Eds.): W2GIS 2007, LNCS 4857, pp. 61–75, 2007. c  Springer-Verlag Berlin Heidelberg 2007