jp-evalb: Robust Alignment-based PARSEVAL Measures
Jungyeul Park, Junrui Wang, Eunkyul Leah Jo, Angela Yoonseo Park
TL;DR
This paper addresses limitations of the traditional PARSEVAL evaluation (evalb) which assumes exact tokenization and sentence boundaries. It introduces jp-evalb, an alignment-based method that pre-aligns sentences and words to enable robust PARSEVAL measurement in end-to-end parsing pipelines, including cases with tokenization or boundary mismatches. The authors detail the algorithm, mismatch handling (word and sentence), and key assumptions, and demonstrate through case studies on Penn Treebank Section 23, evalb bug scenarios, and Korean end-to-end parsing that jp-evalb reproduces evalb results when desired while offering improved handling of mismatches. The work provides an open-source implementation, preserving compatibility with PARSEVAL while enabling broader, more realistic evaluation in contemporary parsing systems.
Abstract
We introduce an evaluation system designed to compute PARSEVAL measures, offering a viable alternative to \texttt{evalb} commonly used for constituency parsing evaluation. The widely used \texttt{evalb} script has traditionally been employed for evaluating the accuracy of constituency parsing results, albeit with the requirement for consistent tokenization and sentence boundaries. In contrast, our approach, named \texttt{jp-evalb}, is founded on an alignment method. This method aligns sentences and words when discrepancies arise. It aims to overcome several known issues associated with \texttt{evalb} by utilizing the `jointly preprocessed (JP)' alignment-based method. We introduce a more flexible and adaptive framework, ultimately contributing to a more accurate assessment of constituency parsing performance.
