🤖 AI Summary
Existing multilingual instruction-following benchmarks heavily rely on machine translation, introducing cross-lingual evaluation bias—particularly underestimating model capabilities in low-resource languages. To address this, we propose Marco-Bench-MIF, the first multilingual instruction-following benchmark covering 30 languages with systematic, multi-level localization. Its construction paradigm integrates human localization with rigorous translation verification, explicitly handling language-specific features—including casing, proper nouns, and cultural references. Experiments show that localized data improves accuracy by 7–22% over machine-translated counterparts; scaling model size yields 45–60% performance gains, yet script differences remain a significant challenge. Marco-Bench-MIF reveals pronounced performance disparities between high- and low-resource languages and establishes a new standard for fair, robust multilingual instruction-following evaluation.
📝 Abstract
Instruction-following capability has become a major ability to be evaluated for Large Language Models (LLMs). However, existing datasets, such as IFEval, are either predominantly monolingual and centered on English or simply machine translated to other languages, limiting their applicability in multilingual contexts. In this paper, we present an carefully-curated extension of IFEval to a localized multilingual version named Marco-Bench-MIF, covering 30 languages with varying levels of localization. Our benchmark addresses linguistic constraints (e.g., modifying capitalization requirements for Chinese) and cultural references (e.g., substituting region-specific company names in prompts) via a hybrid pipeline combining translation with verification. Through comprehensive evaluation of 20+ LLMs on our Marco-Bench-MIF, we found that: (1) 25-35% accuracy gap between high/low-resource languages, (2) model scales largely impact performance by 45-60% yet persists script-specific challenges, and (3) machine-translated data underestimates accuracy by7-22% versus localized data. Our analysis identifies challenges in multilingual instruction following, including keyword consistency preservation and compositional constraint adherence across languages. Our Marco-Bench-MIF is available at https://github.com/AIDC-AI/Marco-Bench-MIF.