Finally, we define the following reranking objective: 3.6 Training and Inference Rather than separately training each component, we propose an end-to-end training strategy so that downstream components (e.g., the reader) can benefit from the high-quality upstream outputs (e.g., the retrieved segments) during training.
we take a multi-task learning approach (Caruna, 1993;Ruder, 2017), sharing the parameters of earlier blocks with a joint objective function defined as: Algorithm 2 details the training process.