Ranking search results using a single ranking function for all search engine visitors is inherently bounded in the performance the ranking algorithm can achieve when considering the variety of requirements of Web searchers and the proliferation of topics and types of data modern search engines rank. Adding a geographical dimension to the mix by way of local search engines further reduces the average satisfaction a ranking algorithm can garner from local search users. Personalization has been proposed in Web search with some success but has not, to our knowledge, been investigated thoroughly in local search. As initial steps in local search personalization, we propose a model for personalizing search results in a local search engine using a hybrid of profile- and click-based user modeling methods. User profiles are used to compare local search results to the topical interests of users and the specific businesses in which they have shown interest by way of search result “clicks”. Our model is tested through a user study and is shown to result in significantly improved mean average precision over the baseline ranking system.

Traditional ranking schemes of the relevance of a Web page to a user query in a search engine are less appropriate when the search term contains geographic information. Often, geographic entities, such as addresses, city names, and location names, appear only once or twice in a Web page, and are typically not in a heading or larger font. Consequently, an alternative ranking approach to the traditional weighted tf*idf relevance ranking is need. Further, if a Web site contains a geographic entity, it is often the case that its in- and out-neighbours do not refer to the same entity, although they may refer to other geographic entities. We present a local search engine that applies a novel ranking algorithm suitable for ranking Web pages with geographic content. We describe its major components: geographic ranking, focused crawling, geographic extractor, and the related web-sites feature.

This paper introduces a novel link-based ranking algorithm based on a model of focused Web surfers. FocusedRank is described and compared to implementations of PageRank and Topic-Sensitive PageRank. We report a user study that measures the relevance and precision of each approach. FocusedRank gives superior relevancy over PageRank, while significantly reducing the computational complexity compared to the Topic-Senstivice PageRank.

A collaborative crawler is a group of crawling nodes, in which each crawling node is responsible for a specific portion of the web. We study the problem of collecting geographi-cally-aware pages using collaborative crawling strategies. We first propose several collaborative crawling strategies for the geographically focused crawling, whose goal is to collect web pages about specified geographic locations, by considering features like URL address of page, content of page, extended anchor text of link, and others. Later, we propose various evaluation criteria to qualify the performance of such crawling strategies. Finally, we experimentally study our crawling strategies by crawling the real web data showing that some of our crawling strategies greatly outperform the simple URL-hash based partition collaborative crawling, in which the crawling assignments are determined according to the hash-value computation over URLs. More precisely, features like URL address of page and extended anchor text of link are shown to yield the best overall performance for the geographically focused crawling.