Dimitrios Androutsos

Neural rankers are typically trained with surrogate objectives because target evaluation metrics such as Normalized Discounted Cumulative Gain (NDCG) are non-differentiable. Existing approaches rely on hand-designed surrogate losses or fixed smooth relaxations, which can be misaligned with the ta...

Modern information retrieval pipelines combine retrieval, LLM-based generation, and LLM-based judgment, and a poor outcome may originate in any of the three stages. Existing work studies these failures in isolation. This paper instead asks whether query difficulty itself transfers across the thre...