This paper describes the participation of the LIA team in the English Subtopic Mining subtask of the NTCIR-10 INTENT-2 Task. The goal of this task was to specialize or dis-ambiguate web search queries by identifying the different subtopics that could refer to these queries. Our motivation was to take a conceptual approach, therefore representing the query by a set of concepts before identifying the related subtopics. However we seem to have misunderstood the real point of this task, which was in fact focused on generating web query suggestion: official results therefore do not show support for our initial motivation.