Konrad Rieck
Author directory2026
What Are We Measuring in NLG? A Meta-Analysis of Evaluation Trends 2020-2025
Jing Yang | Nils Feldhus | Salar Mohtaj | Leonhard Hennig | Qianli Wang | Eleni Metheniti | Sherzod Hakimov | Charlott Jakob | Veronika Solopova | Konrad Rieck | David Schlangen | Sebastian Möller | Vera Schmitt
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Jing Yang | Nils Feldhus | Salar Mohtaj | Leonhard Hennig | Qianli Wang | Eleni Metheniti | Sherzod Hakimov | Charlott Jakob | Veronika Solopova | Konrad Rieck | David Schlangen | Sebastian Möller | Vera Schmitt
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
As Natural Language Generation (NLG) dominates modern NLP, scalable evaluation remains a critical bottleneck. Consequently, LLM-as-a-judge (LaaJ) adoption has accelerated rapidly, appearing in more papers than human evaluation in 2025. This pivotal shift motivates a critical analysis of current evaluation practices. Overcoming the limits of rigid keyword filtering and manual review, we employ a multi-LLM information extraction pipeline to gather structured metadata from 14,171 papers across four major NLP conferences (2020–2025). Analyzing 3,334 filtered NLG papers, we identify three systemic challenges. (1) Metric inertia: despite the shift toward open-ended generation, legacy lexical metrics (BLEU, ROUGE) persist as primary indicators, typically used alongside rather than replaced by semantic alternatives. (2) Metric-criteria mapping problem: our paper-level co-occurrence data reveals that general-purpose automatic metrics are applied as broad proxies for quality, without specifying which dimension of text generation they are intended to evaluate. (3) Validation gap: LaaJ has grown rapidly without commensurate human validation (fewer than 8% of papers). Crucially, while LaaJ correlates with aggregate quality, alignment collapses on fine-grained criteria like fluency. To address these gaps, we distill our findings into a minimal Evaluation Checklist to guide metric selection, construct validity, and LaaJ deployment.