Target Type Identification

A characteristic property of entities is that they are typed. Naturally, entity-bearing queries may be complemented with target types (types of its relevant entities). Given a search query, Target Type Identification (TTI) is the task of returning a ranked list of types from an underlying type taxonomy. Entity retrieval performance can be significantly improved when explicit target type information is identified for a query.

The following methods for target type identification are implemented in Nordlys:

Benchmark results

Below, we present retrieval results on the target type identification in [Garigliotti et al., 2017].

Method NDCG@1 NDCG@5
EC, BM25 (K = 20) 0.1490 0.3223
EC, LM (K = 20) 0.1417 0.3161
TC, BM25 0.2015 0.3109
TC, LM 0.2341 0.3780
LTR 0.4842 0.6355

The corresponding files with rankings can be found on Github, specifically under output directory.


  • Darío Garigliotti, Faegheh Hasibi, and Krisztian Balog. Target Type Identification for Entity-Bearing Queries. In: 40th International ACM SIGIR Conference on Research and Development in Information Retrieval (SIGIR ’17). [BIB] [PDF]
  • Krisztian Balog, Robert Neumayer. 2012. Hierarchical target type identification for entity-oriented queries. In Proceedings of the 21st ACM International Conference on Information and Knowledge Management (CIKM ‘12). 2391–2394. [BIB] [PDF]
  • Shuo Zhang and Krisztian Balog. Design Patterns for Fusion-Based Object Retrieval. In: Jose J. et al. (eds) Advances in Information Retrieval (ECIR ‘17). Lecture Notes in Computer Science, vol 10193. Springer, Cham. 684-690. [BIB] [PDF]