Performance Prediction for Multi-hop Questions
Mohammadreza Samadi Davood Rafiei
We study the problem of Query Performance Prediction (QPP) for open-domain
multi-hop Question Answering (QA), where the task is to estimate the difficulty
of evaluating a multi-hop question over a corpus. Despite the extensive
research on predicting the performance of ad-hoc and QA retrieval models, there
has been a lack of study on the estimation of the difficulty of multi-hop
questions. The problem is challenging due to the multi-step nature of the
retrieval process, potential dependency of the steps and the reasoning
involved. To tackle this challenge, we propose multHP, a novel pre-retrieval
method for predicting the performance of open-domain multi-hop questions. Our
extensive evaluation on the largest multi-hop QA dataset using several modern
QA systems shows that the proposed model is a strong predictor of the
performance, outperforming traditional single-hop QPP models. Additionally, we
demonstrate that our approach can be effectively used to optimize the
parameters of QA systems, such as the number of documents to be retrieved,
resulting in improved overall retrieval performance.