Peter Ebert Christensen
Author directory2026
What and Whose Knowledge? Measuring Epistemic Diversity in Large Language Models
Dustin Wright | Sarah Masud | Jared Moore | Srishti Yadav | Maria Antoniak | Peter Ebert Christensen | Chan Young Park | Isabelle Augenstein
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Dustin Wright | Sarah Masud | Jared Moore | Srishti Yadav | Maria Antoniak | Peter Ebert Christensen | Chan Young Park | Isabelle Augenstein
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Large language models (LLMs) are increasingly used as primary knowledge sources, yet their epistemic diversity — defined as the diversity of real-world claims in their outputs — has never been measured. The dominant paradigm is that overall LLM diversity is low, but this is always with respect to a single point in time, with no reference baseline or consideration for variation across countries. We address this by performing the first systematic study of epistemic diversity in LLMs across time and cultural context, testing 27 LLMs on 155 topics covering 12 countries, resulting in 1.7M responses and 70M individual claims. We find that epistemic diversity has increased substantially over the past three years, a positive counter to recent diversity pessimism. However, despite progress, we find that every LLM is less diverse than a search baseline. The gap is not uniform: RAG can improve diversity, while larger models are counterintuitively less diverse than smaller ones. Moreover, LLMs systematically reflect English-language knowledge over local-language knowledge for country specific topics. Together, these results demonstrate that while progress on epistemic diversity is tangible, it is insufficient and unevenly distributed.
2025
A Template Is All You Meme
Luke Bates | Peter Ebert Christensen | Preslav Nakov | Iryna Gurevych
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
Luke Bates | Peter Ebert Christensen | Preslav Nakov | Iryna Gurevych
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
Templatic memes, characterized by a semantic structure adaptable to the creator’s intent, represent a significant yet underexplored area within meme processing literature. With the goal of establishing a new direction for computational meme analysis, here we create a knowledge base composed of more than 5,200 meme templates, information about them, and 54,000 examples of template instances (templatic memes). To investigate the semantic signal of meme templates, we show that we can match memes in datasets to base templates contained in our knowledge base with a distance-based lookup. To demonstrate the power of meme templates, we create TSplit, a method to reorganize datasets, where a template or templatic instance can only appear in either the training or test split. Our re-split datasets enhance general meme knowledge and improve sample efficiency, leading to more robust models. Our examination of meme templates results in state-of-the-art performance for every dataset we consider, paving the way for analysis grounded in templateness.