Search

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.

We describe DCU’s participation in the NTCIR-12 SpokenQuery&Doc (SQD-2) task. In the context of the slide-group retrieval sub-task, we experiment with a passage retrieval method that re-scores each passage according to the relevance score of the document from which the passage is taken. This is performed by linearly interpolating their relevance scores which are calculated using the Okapi BM25 model of probabilistic retrieval for passages and documents independently. In conjunction with this, we assess the benefits of using pseudo-relevance feedback for expanding the textual representation of the spoken queries with terms found in the top-ranked documents and passages, and experiment with a general multidimensional optimisation method to jointly tune the BM25 and query expansion parameters with queries and relevance data from the NTCIR-11 SQD-1 task. Retrieval experiments performed over the SQD-1 and SQD-2 queries confirm previous findings which affirm that integrating document information when ranking passages can lead to improved passage retrieval effectiveness. Furthermore, results indicate that no significant gains in retrieval effectiveness can be obtained by using query expansion in combination with our retrieval models over these two query sets.

This paper presents an overview of the Spoken Query and Spoken Document retrieval (SpokenQuery&Doc-2) task at the NTCIR-12 Workshop. This task included spoken query driven spoken content retrieval (SQ-SCR) and a spoken query driven spoken term detection (SQ-STD) as the two subtasks. The paper describes details of each sub-task, the data used, the creation of the speech recognition systems used to create the transcripts, the design of the retrieval test collections, the metrics used to evaluate the sub-tasks and a summary of the results of submissions by the task participants.