Batayan: A Filipino NLP benchmark for evaluating Large Language Models

TL;DR

Batayan is a comprehensive Filipino NLP benchmark that evaluates large language models across understanding, reasoning, and generation tasks, addressing resource gaps and linguistic complexities of Filipino.

Contribution

It introduces eight new Filipino NLP tasks, including three novel ones, with a native-speaker-driven validation process, and provides a public evaluation suite for community progress.

Findings

Significant performance gaps in LLMs on Filipino tasks.

Under-representation of Filipino in pre-training data.

Challenges due to Filipino's morphology and syntax.

Abstract

Recent advances in large language models (LLMs) have demonstrated remarkable capabilities on widely benchmarked high-resource languages. However, linguistic nuances of under-resourced languages remain unexplored. We introduce Batayan, a holistic Filipino benchmark that systematically evaluates LLMs across three key natural language processing (NLP) competencies: understanding, reasoning, and generation. Batayan consolidates eight tasks, three of which have not existed prior for Filipino corpora, covering both Tagalog and code-switched Taglish utterances. Our rigorous, native-speaker-driven adaptation and validation processes ensures fluency and authenticity to the complex morphological and syntactic structures of Filipino, alleviating the pervasive translationese bias in existing Filipino corpora. We report empirical results on a variety of open-source and commercial LLMs, highlighting significant performance gaps that signal the under-representation of Filipino in pre-training corpora, the unique hurdles in modeling Filipino's rich morphology and construction, and the importance of explicit Filipino language support. Moreover, we discuss the practical challenges encountered in dataset construction and propose principled solutions for building culturally and linguistically-faithful resources in under-represented languages. We also provide a public evaluation suite as a clear foundation for iterative, community-driven progress in Filipino NLP.