Designing a Query Language Using Keyword Pairs for Spatial and Temporal Search.

Our goal is to design a query language based on two keywords for spatial and temporal search by using a single textual query in an intuitive way. This language as a form of syntactic sugar can express complex spatio-temporal queries which include conditions on range, direction, time length and size which are difficult to express through textual queries in conventional keyword-based search systems. To express these conditions, our proposed language introduces 12 spatio-temporal operators such as arithmetic and directional operators which enables users to combine and manipulate spatial and temporal areas. Also, we use "space characters" (the space-key) between keywords which are used to express the geographical distance or time-length between matching objects in an intuitive way for general users. In this paper, we provide an overview of our proposed search system where we can retrieve maps and web documents to highlight how the query language could be put into practice by using complex spatio-temporal queries. Finally, we discuss the results of a user study carried out to evaluate the potential usefulness of our proposed search system.