Lesia Ivashkevych
2026
Semantic Fidelity Versus Literary Quality: A Construct Validity Study of Neural Machine Translation Metrics
Dmytro Chaplynskyi | Ivan Kulynych | Maria Shvedova | Lesia Ivashkevych
Proceedings of the Fifth Ukrainian Natural Language Processing Conference (UNLP 2026)
Dmytro Chaplynskyi | Ivan Kulynych | Maria Shvedova | Lesia Ivashkevych
Proceedings of the Fifth Ukrainian Natural Language Processing Conference (UNLP 2026)
Automatic machine translation metrics are the de facto standard for evaluating translation quality. Yet, it remains unclear what they actually measure. We investigate this question using a unique multilingual corpus: seven human Ukrainian translations of George Orwell’s Animal Farm, alongside three architecturally distinct AI systems (GPT-5.2, DeepL, and Lapa, a Ukrainian-tuned LLM). Across seven neural metrics, four reference-free and three reference-based, all three AI translations rank at the top. However, stylometric analysis exposes that these same AI translations are not as lexically rich as human ones ($-$18% MTLD), underuse Ukrainian particles (up to 2x fewer) and diminutive morphology (2.6x fewer), and converge on near-identical outputs (LaBSE pairwise similarity 0.941 vs. 0.711 for human pairs). A controlled LLM-as-a-judge experiment demonstrates a clear preference reversal: when the English source is visible, AI ranks first; when it is hidden and the judge evaluates literary quality alone, humans rise to the top and AI falls to the lower ranks. Human evaluation (1,034 pairwise judgments) is balanced across both patterns. We argue that current MT metrics reward semantic fidelity and surface fluency — properties optimized by AI systems — while failing to capture the lexical richness, cultural adaptation, and stylistic voice that characterize skilled literary translation.
Professional Translators Versus Quality Estimation Models: Reliability and Agreement in English-Ukrainian Translation Evaluation
Dmytro Chaplynskyi | Kyrylo Zakharov | Lesia Ivashkevych
Proceedings of the Fifth Ukrainian Natural Language Processing Conference (UNLP 2026)
Dmytro Chaplynskyi | Kyrylo Zakharov | Lesia Ivashkevych
Proceedings of the Fifth Ukrainian Natural Language Processing Conference (UNLP 2026)
We extend a prior study comparing automatic Quality Estimation (QE) models with crowdsourced student judgments for English–Ukrainian parallel corpus evaluation. Eight professional translators each rate 1,000 sentence pairs on a continuous 0–100 scale under one of two paradigms: holistic quality scoring or a two-stage fluency-plus-adequacy protocol, with a repeated task for test–retest reliability. Professionals using the holistic scale achieve significantly higher inter-rater reliability than both linguistics students and professionals using separate fluency and adequacy scales, contradicting the expectation that multidimensional evaluation improves agreement. Adequacy correlates strongly with holistic judgments while fluency emerges as a largely independent dimension. Experts also exhibit a significant leniency drift over the session, alongside increasing evaluation speed. We additionally evaluate three LLMs as translation quality judges (Gemini 3 Flash, GPT-5.4, Gemma 3 27B) and find that the two larger models modestly outperform dedicated QE models in correlation with expert scores (r = 0.814–0.821 vs. r ≤ 0.747). When prompted for separate fluency and adequacy scores, the LLMs replicate the adequacy-dominance pattern, confirming that meaning preservation drives holistic quality perception across both human and machine judges.