Corrected Evaluation Results of the NTCIR WWW-2, WWW-3, and WWW-4 English Subtasks

TL;DR

This paper corrects the evaluation results of the NTCIR WWW-2, WWW-3, and WWW-4 tasks by fixing a bug in the relevance assessment interface, providing accurate results for future research and comparisons.

Contribution

It identifies and corrects a critical bug in the relevance labels used in NTCIR WWW tasks, ensuring accurate evaluation results for these benchmarks.

Findings

Corrected relevance labels for WWW-2, WWW-3, and WWW-4

Revealed the impact of the bug on previous evaluation results

Provided accurate benchmark results for future research

Abstract

Unfortunately, the official English (sub)task results reported in the NTCIR-14 WWW-2, NTCIR-15 WWW-3, and NTCIR-16 WWW-4 overview papers are incorrect due to noise in the official qrels files; this paper reports results based on the corrected qrels files. The noise is due to a fatal bug in the backend of our relevance assessment interface. More specifically, at WWW-2, WWW-3, and WWW-4, two versions of pool files were created for each English topic: a PRI ("prioritised") file, which uses the NTCIRPOOL script to prioritise likely relevant documents, and a RND ("randomised") file, which randomises the pooled documents. This was done for the purpose of studying the effect of document ordering for relevance assessors. However, the programmer who wrote the interface backend assumed that a combination of a topic ID and a document rank in the pool file uniquely determines a document ID; this is obviously incorrect as we have two versions of pool files. The outcome is that all the PRI-based relevance labels for the WWW-2 test collection are incorrect (while all the RND-based relevance labels are correct), and all the RND-based relevance labels for the WWW-3 and WWW-4 test collections are incorrect (while all the PRI-based relevance labels are correct). This bug was finally discovered at the NTCIR-16 WWW-4 task when the first seven authors of this paper served as Gold assessors (i.e., topic creators who define what is relevant) and closely examined the disagreements with Bronze assessors (i.e., non-topic-creators; non-experts). We would like to apologise to the WWW participants and the NTCIR chairs for the inconvenience and confusion caused due to this bug.