By Herbert Ullrich
Review Details
Reviewer has chosen not to be Anonymous
Overall Impression: Weak
Content:
Technical Quality of the paper: Weak
Originality of the paper: Yes
Adequacy of the bibliography: Yes, but see detailed comments
Presentation:
Adequacy of the abstract: Yes
Introduction: background and motivation: Good
Organization of the paper: Needs improvement
Level of English: Satisfactory
Overall presentation: Average
Detailed Comments:
The paper proposes a parser-independent, morphology-aware framework for relation extraction in low-resource agglutinative languages, using Manipuri (Meiteilon) as the case study. Each sentence is converted into a heterogeneous graph in which lexical roots, grammatical affixes, and entity mentions are explicit nodes connected by typed edges (HAS_AFFIX, NEXT_TOKEN, SPAN_OF, SELF_LOOP), node representations are learned with a two-layer R-GCN, and relation classification is performed by a Tsetlin Machine (TM) over binary symbolic features plus binarized R-GCN embeddings. A new dataset (MERED) is introduced, and the system reports 91.72% accuracy / 91.16% Macro-F1, ahead of BiLSTM, CNN–BiLSTM, dependency-GCN, and XLM-R baselines.
I think the core idea is genuinely appealing and a good fit for a neurosymbolic venue: promoting role-marking affixes to first-class graph nodes is a clean way to inject morphology into message passing, and pairing an R-GCN encoder with a Tsetlin Machine gives a credible interpretability story.
The motivation and linguistic framing are well written. My concerns are concentrated in the experimental section. As part of the review I downloaded and inspected the released dataset and code repository (as of June 16, 2026), and I was not able to reconcile the reported experiments with those artifacts on several points. I describe each observation factually below; in several places there may be a straightforward explanation (for example, a more complete dataset or additional scripts that were not yet added to the public release), and if so, I would ask the authors to provide the exact artifacts so the results can be verified.
Strengths
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1. Well-motivated, well-scoped problem. Morphology-as-structure for agglutinative, low-resource RE is clearly argued, the parser-independence motivation is convincing.
2. Conceptually elegant architecture. Affixes as graph nodes + relation-specific R-GCN message passing + a symbolic TM classifier is a natural, defensible design.
3. Interpretability angle. Translating embeddings into propositional clauses fits the venue, and the neurosymbolic "bridge" analysis (Table 7) is a nice idea.
4. New resource + public code. A Manipuri RE dataset and a public repository are valuable for an under-resourced language, provided the released artifacts can be matched to the reported results.
Major points (please address)
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M1: I could not reconcile the released dataset with the reported results.
Using the provided Kaggle and GitHub links, I could not reproduce the 495-sample MERED dataset referred throughout the article. Both released JSON files only contain 25 sentences and 43 relations (although the github version in MERED.json seems to feature some duplicates), which is an order of magnitude less than the 495 relations refered in Tables 8-13 and in the confusion matrix. Both files also mark samples with "annotation_status": "auto + heuristic" metadata, which seems to contrast the manual annotation claim made in paper (page 5). Releasing the used dataset as stated in page 11-12 (Data availability) would resolve this confusion.
M2: Released code is incomplete as published
The entry-point scripts import modules that are not present in the repository - rgcn_encoder.py (the R-GCN definition), tm_features.py (candidate-pair features), and evaluation.py (metrics). The TM training script named in the README (tm_train_encode_positive.py) and the default MERED data file used by every script (MERED_reduced_relations_v2.json) are also absent. As a result the pipeline cannot currently be run end-to-end from the public repository. For a paper whose contributions include interpretability and reproducibility, completing the release (including a runnable example and the exact data) would substantially strengthen it.
M3: The abstract-listed score has no explicit held-out test-split
While the article does not address the train/test splitting of MERED dataset used for experimentation at all, upon investigating the attached training and evaluation scripts, the TM seems (as per pipeline_eval_tm_with_encode_positive_new.py) to be applied to all pairs from the full dataset, with no train/test partition in the evaluation path. Please report a disjoint, reproducible test split, so the reported metrics are clearly on unseen data.
M4: The abstract-listed score is on a positive-only subset; end-to-end RE is not reported.
The strongest result is computed on the 495 positive instances after candidate pruning ("to mitigate the dominance of the NONE class"). This gives a performance metric of relation classification given that relation exists, rather than that of an end-to-end relationship extraction. Please add the realistic end-to-end numbers, including the NONE class.
M5: Dataset documentation
As a stated contribution, MERED should come with corpus statistics (sentences/documents, entities, per-class relation counts on the full corpus), annotation details (number of annotators, guidelines, inter-annotator agreement), and the train/dev/test split used. None of these are currently given, and with so few instances per class, confidence intervals or cross-validation would help establish that the results are stable.
M6: The baselines and ablations may benefit from further clarification
Some reported numbers are unexpectedly low or unstable, especially the neural R-GCN + MLP ablation with Macro-F1 0.16 and the XLM-R baseline with near-zero scores for many classes. These results may be correct in this low-resource setting, but the paper should at least briefly explain their training setup. Without this, it is difficult to know whether the large gains come from the proposed neuro-symbolic design, from the positive-only setup, from feature engineering/candidate filtering, or from under-optimized baselines.
Minor / presentation
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- Broken cross-reference: "…further analyzed in Section ." (empty reference).
- Introduction and Review of Literature overlap substantially; please consolidate.
- Bibliography: several author fields look mis-parsed where "et al." became a first name ("A. e. a. Conneau", "X. e. a. He", "J. e. a. Devlin", "D. e. a. Zeng", "J. e. a. Nivre"); duplicate entries appear — Comrie 1989a/1989b (same book), Haspelmath 2002/2010 (same Understanding Morphology), Schlichtkrull 2018a/2018b (same ESWC paper), Wu et al. 2021a/2021b (identical survey), and multiple Zeng entries. Please de-duplicate and correct.
- Segmentation is not evaluated although the pipeline depends on the greedy suffix segmenter; it might be worth reporting its accuracy/coverage or discussing its possible error contribution.
- Transferability claims to Uyghur/Bodo/Santali/Kokborok are asserted but not demonstrated; I would suggest to slightly soften them (or add at least one transfer experiment).
Recommendation rationale
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I recommend Major revisions. The core idea is original, interesting, and well suited to the venue, and the manuscript has a plausible contribution if the empirical claims can be verified. However, the present version has serious reproducibility and evaluation gaps: the released dataset/code do not appear to match the reported experiments, the train/test split is unclear, and the headline score is reported on a positive-only subset rather than a full end-to-end RE setting.
I would be happy to reassess the paper if the authors provide the exact dataset and splits used for the reported results, code, or a more complete description of the experiments that produced the numbers.