Evaluating Discourse Representation Structure (DRS)-based systems for semantic parsing (Text-to-DRS) and generation (DRS-to-Text) poses unique challenges, particularly in low-resource languages like Urdu. Traditional metrics often fall short, focusing either on structural accuracy or linguistic quality, but rarely capturing both. To address this limitation, we introduce two complementary evaluation methodologies—Parse-Generate (PARS-GEN) and Generate-Parse (GEN-PARS)—designed for a more comprehensive assessment of DRS-based systems. PARS-GEN evaluates the parsing process by converting DRS outputs back to the text, revealing linguistic nuances often missed by structure-focused metrics like SMATCH. Conversely, GEN-PARS assesses text generation by converting generated text into DRS, providing a semantic perspective that complements surface-level metrics such as BLEU, METEOR, and BERTScore. Using the Parallel Meaning Bank (PMB) dataset, we demonstrate our methodology across Urdu, uncovering unique insights into Urdu’s structural and linguistic interplay. Findings show that traditional metrics frequently overlook the complexity of linguistic and semantic fidelity, especially in low-resource languages. Our dual approach offers a robust framework for evaluating DRS-based systems, enhancing semantic parsing and text generation quality.

Semantic parsing and text generation exhibit reversible properties when utilizing Discourse Representation Structures (DRS). However, both processes—text-to-DRS parsing and DRS-to-text generation—are susceptible to errors. In this paper, we exploit the reversible nature of DRS to explore both error propagation, which is commonly seen in pipeline methods, and the less frequently studied potential for error correction. We investigate two pipeline approaches: Parse-Generate-Parse (PGP) and Generate-Parse-Generate (GPG), utilizing pre-trained language models where the output of one model becomes the input for the next. Our evaluation uses the Parallel Meaning Bank dataset, focusing on Urdu as a low-resource language, Italian as a mid-resource language, and English serving as a high-resource baseline. Our analysis highlights that while pipelines are theoretically suited for error correction, they more often propagate errors, with Urdu exhibiting the greatest sensitivity, Italian showing a moderate effect, and English demonstrating the highest stability. This variation highlights the unique challenges faced by low-resource languages in semantic processing tasks. Further, our findings suggest that these pipeline methods support the development of more linguistically balanced datasets, enabling a comprehensive assessment across factors like sentence structure, length, type, polarity, and voice. Our cross-linguistic analysis provides valuable insights into the behavior of DRS processing in low-resource contexts, demonstrating both the potential and limitations of reversible pipeline approaches.

Neural networks are notoriously data-hungry. This represents an issue in cases where data are scarce such as in low-resource languages. Data augmentation is a technique commonly used in computer vision to provide neural networks with more data and increase their generalization power. When dealing with data augmentation for natural language, however, simple data augmentation techniques similar to the ones used in computer vision such as rotation and cropping cannot be employed because they would generate ungrammatical texts. Thus, data augmentation needs a specific design in the case of neural logic-to-text systems, especially for a structurally rich input format such as the ones used for meaning representation. This is the case of the neural natural language generation for Discourse Representation Structures (DRS-to-Text), where the logical nature of DRS needs a specific design of data augmentation. In this paper, we adopt a novel approach in DRS-to-Text to selectively augment a training set with new data by adding and varying two specific lexical categories, i.e. proper and common nouns. In particular, we propose using WordNet supersenses to produce new training sentences using both in-and-out-of-context nouns. We present a number of experiments for evaluating the role played by augmented lexical information. The experimental results prove the effectiveness of our approach for data augmentation in DRS-to-Text generation.