This paper introduces the concept of spatial filters as an approach
to increasing the relevance of the information retrieved by users
of mobile information systems. This approach applies post-query
filters to remove results that are deemed not relevant given some
aspect of a mobile individual’s spatial behaviour. The aim is to
reduce the volume of results returned to users of mobile
information systems, to avoid the need for manual filtering. An
opportunity for future research is to consider how these filters can
be applied to the task of combining rankings based upon thematic
and spatial criteria, for documents retrieved from unstructured or
semi-structured collections, such as those handled by geographic
information retrieval systems.