Geo-Temporal retrieval filtering versus answer resolution using Wikipedia

We describe an evaluation experiment on GeoTemporal Document Retrieval created for the GeoTime evaluation task of NTCIR 2011. This work describes the retrieval techniques developed to accomplish this task. We describe the collections used in the workshop, detailing the composition of the collections in terms of geographic and temporal expressions. The first contribution of this work is the collections’ statistics, which by itself reveals the relevance of this subject. Our parsing techniques found millions of references related with the dimensions of relevance time and space. Those references were used to index the documents in order to score them in those dimensions. We also introduce a technique to find extra references in Wikipedia using Google Search Service and the same parsers used in the collections. Those references were used in four different scenarios depending on the queries: first we used the references found in topics to filter documents without geographic or temporal expressions and used pseudo relevance feedback to expand topics with no references using the indexes created for places and dates; in other approach we used the Wikipedia references to filter documents from the result set, in a last approach we expanded all topics with the Wikipedia references. Finally we used another technique based on metric distances calculated through coordinates (latitudes and longitudes) and dates in order to create a scope for documents and topics, and rank them according to the distance between each other.