Thematic maps are widely used to analyse spatial phenomena in the world. With the rapid development of Internet and GIS technology, people have access to a variety of thematic maps. Nonetheless, these web-based systems often restricts their contents to maps already edited and stored in databases, rather than allowing users to collect data form different sources and create thematic maps meeting their demands. Imagine if a person has a hypothesis about a correlation between number of conflicts and level of poverty in Africa. She wants to see "a map showing the relationship between armed conflicts in Africa and the level of poverty". If she types this into the Google search engine today she might get some useful results, but not the map she is requesting. The search engine is not able to extract the meaning of the query. The results she gets contain all the words she typed in, but the meaning of “relationship” in her request is often about other issues than conflicts and poverty...