Uncertainty Quantification (UQ) for Natural Language Generation (NLG) is crucial for assessing the performance of Large Language Models (LLMs), as it reveals confidence in predictions, identifies failure modes, and gauges output reliability. Conformal Prediction (CP), a model-agnostic method that generates prediction sets with a specified error rate, has been adopted for UQ in classification tasks, where the size of the prediction set indicates the model's uncertainty. However, when adapting CP to NLG, the sampling-based method for generating candidate outputs cannot guarantee the inclusion of the ground truth, limiting its applicability across a wide range of error rates. To address this, we propose \ourmethod, a method that explicitly adds the ground truth to the candidate outputs and uses logit scores to measure nonconformity. Our experiments with six LLMs on four NLG tasks show that \ourmethod outperforms baseline methods in calibrating error rates and empirical cover rates, offering accurate UQ across a wide range of user-specified error rates.

Warming temperatures mean shorter ice seasons in Sanikiluaq, Nunavut. As a result, the stretches of landfast ice formed from frozen seawater that Inuit use to travel and hunt on are increasingly unpredictable and unsafe. Polynyas, areas of open water and thin ice, occur where ocean currents or wind prevent pack ice from forming. They're typically found in the same locations each year enabling travellers to plan their routes safely. But climate change is affecting this predictability, causing smaller, unexpected polynyas that make travelling across the pack ice risky.

Video shows how narwhals use their iconic tusks to hunt fish. Filmed near Nunavut, Canada, a narwhal can be seen tapping a fish with its tusk. The unicorn of the sea just got a little less mysterious. Until now, how narwhals used their long tusks had been subject to much speculation by scientists. Behavior captured for the first time on camera shows narwhals using the long tusks protruding from their heads to stun Arctic cod by hitting them, using jagged, quick movements.