Are Large Language Model-based Evaluators the Solution to Scaling Up
  Multilingual Evaluation?
Authors: name: Rishav Hada, name: Varun Gumma, name: Adrian de Wynter, name: Harshita Diddee, name: Mohamed Ahmed, name: Monojit Choudhury, name: Kalika Bali, name: Sunayana Sitaram

Large Language Models (LLMs) have demonstrated impressive performance on
Natural Language Processing (NLP) tasks, such as Question Answering,
Summarization, and Classification. The use of LLMs as evaluators, that can rank
or score the output of other models (usually LLMs) has become increasingly
popular, due to the limitations of current evaluation techniques including the
lack of appropriate benchmarks, metrics, cost, and access to human annotators.
While LLMs are capable of handling approximately 100 languages, the majority of
languages beyond the top 20 lack systematic evaluation across various tasks,
metrics, and benchmarks. This creates an urgent need to scale up multilingual
evaluation to ensure a precise understanding of LLM performance across diverse
languages. LLM-based evaluators seem like the perfect solution to this problem,
as they do not require human annotators, human-created references, or
benchmarks and can theoretically be used to evaluate any language covered by
the LLM. In this paper, we investigate whether LLM-based evaluators can help
scale up multilingual evaluation. Specifically, we calibrate LLM-based
evaluation against 20k human judgments of five metrics across three
text-generation tasks in eight languages. Our findings indicate that LLM-based
evaluators may exhibit bias towards higher scores and should be used with
caution and should always be calibrated with a dataset of native speaker
judgments, particularly in low-resource and non-Latin script languages.