Overview of the NTCIR-15 data search task

NTCIR-15 Data Search is a shared task on ad-hoc retrieval for governmental statistical data. The first round of Data Search focuses on the retrieval of a statistical data collection published by the Japan- ese government (e-Stat), and one published by the US government (Data.gov). This paper introduces the task definition, test collection, and evaluation methodology of NTCIR-15 Data Search. This round of Data Search attracted six research groups, from which we re- ceived 17 submissions for the Japanese subtask, and 37 submissions for the English subtask. The evaluation results of these runs are presented and discussed in this paper.