The RUCIR21 team participated in both the offline and online subtasks of the NTCIR-16 Unbiased Learning to Rank Evaluation (ULTRE) task. This paper describes our approaches and reports the results in the ULTRE task. In the offline subtask, we tried four learning to rank models based on Mobile Click Model (MCM), as well as a revived Dual Learning Algorithm (DLA) model. In the online subtask, we revived a Pairwise Differentiable Gradient Descent (PDGD) run and two online DLA runs, we also tried an online DLA model based on MCM.
Niu et al. (Tue,) studied this question.