Evaluating the Evaluation Metrics for Style Transfer: A Case Study in Multilingual Formality Transfer
This work addresses the problem of inconsistent evaluation practices for researchers in style transfer, particularly in multilingual contexts, though it is incremental as it extends existing evaluations to new languages.
The paper tackled the lack of standardized automatic evaluation metrics in style transfer by evaluating leading metrics on multilingual formality transfer across Brazilian-Portuguese, French, and Italian, identifying models that correlate well with human judgments and are robust across languages.
While the field of style transfer (ST) has been growing rapidly, it has been hampered by a lack of standardized practices for automatic evaluation. In this paper, we evaluate leading ST automatic metrics on the oft-researched task of formality style transfer. Unlike previous evaluations, which focus solely on English, we expand our focus to Brazilian-Portuguese, French, and Italian, making this work the first multilingual evaluation of metrics in ST. We outline best practices for automatic evaluation in (formality) style transfer and identify several models that correlate well with human judgments and are robust across languages. We hope that this work will help accelerate development in ST, where human evaluation is often challenging to collect.