Daniel Cremers


2025

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TurnBack: A Geospatial Route Cognition Benchmark for Large Language Models through Reverse Route
Hongyi Luo | Qing Cheng | Daniel Matos | Hari Krishna Gadi | Yanfeng Zhang | Lu Liu | Yongliang Wang | Niclas Zeller | Daniel Cremers | Liqiu Meng
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing

Humans can interpret geospatial information through natural language, while the geospatial cognition capabilities of Large Language Models (LLMs) remain underexplored. Prior research in this domain has been constrained by non-quantifiable metrics, limited evaluation datasets; unclear research hierarchies further compound these limitations. Therefore, we propose a scalable benchmark and conduct a comprehensive evaluation of the geospatial route cognition of LLMs. We create a large-scale evaluation dataset comprised of 36000 routes from 12 metropolises. Then, we introduce PathBuilder, a novel tool for converting natural language instructions into navigation routes, and vice versa, bridging the gap between geospatial information and natural language. Finally, we propose a new evaluation framework and metrics to rigorously assess 9 state-of-the-art (SOTA) LLMs, on the task of route reversal. The benchmark reveals that LLMs exhibit limited ability to reverse routes: most of the reverse routes neither return to the starting point nor are similar to the optimal route. Additionally, LLMs face challenges such as low robustness in route generation and high confidence for their incorrect answers.

2024

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Quality-Aware Translation Models: Efficient Generation and Quality Estimation in a Single Model
Christian Tomani | David Vilar | Markus Freitag | Colin Cherry | Subhajit Naskar | Mara Finkelstein | Xavier Garcia | Daniel Cremers
Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

Maximum-a-posteriori (MAP) decoding is the most widely used decoding strategy for neural machine translation (NMT) models. The underlying assumption is that model probability correlates well with human judgment, with better translations getting assigned a higher score by the model. However, research has shown that this assumption does not always hold, and generation quality can be improved by decoding to optimize a utility function backed by a metric or quality-estimation signal, as is done by Minimum Bayes Risk (MBR) or Quality-Aware decoding. The main disadvantage of these approaches is that they require an additional model to calculate the utility function during decoding, significantly increasing the computational cost. In this paper, we propose to make the NMT models themselves quality-aware by training them to estimate the quality of their own output. Using this approach for MBR decoding we can drastically reduce the size of the candidate list, resulting in a speed-up of two-orders of magnitude. When applying our method to MAP decoding we obtain quality gains similar or even superior to quality reranking approaches, but with the efficiency of single pass decoding.