Yotam Perlitz
2026
The Mighty ToRR: A Benchmark for Table Reasoning and Robustness in LLMs
Shir Ashury-Tahan | Yifan Mai | Rajmohan C | Ariel Gera | Yotam Perlitz | Asaf Yehudai | Elron Bandel | Leshem Choshen | Eyal Shnarch | Percy Liang | Michal Shmueli-Scheuer
Proceedings of the First Workshop on Structured Understanding, Retrieval, and Generation in the LLM Era (SURGeLLM 2026)
Shir Ashury-Tahan | Yifan Mai | Rajmohan C | Ariel Gera | Yotam Perlitz | Asaf Yehudai | Elron Bandel | Leshem Choshen | Eyal Shnarch | Percy Liang | Michal Shmueli-Scheuer
Proceedings of the First Workshop on Structured Understanding, Retrieval, and Generation in the LLM Era (SURGeLLM 2026)
Despite its real-world significance, model performance on tabular data remains underexplored, leaving uncertainty about which model to rely on and which prompt configuration to adopt. To address this gap, we create ToRR, a benchmark for Table Reasoning and Robustness, measuring model performance and robustness on table-related tasks. The benchmark includes 10 datasets that cover different types of table reasoning capabilities across varied domains. ToRR goes beyond model performance rankings, and is designed to reflect whether models can handle tabular data consistently and robustly, across a variety of common table representation formats. We present a leaderboard as well as comprehensive analyses of the results of leading models over ToRR. Our results reveal a striking pattern of brittle model behavior, where even strong models are unable to perform robustly on tabular data tasks. We further find that no single table format consistently yields superior performance. However, evaluating models across multiple formats is essential for a reliable assessment of their capabilities. Moreover, we show that the reliability boost from testing multiple prompts can be equivalent to adding more test examples. Overall, our findings show that reasoning over table tasks remains a significant challenge. The leaderboard, data and code are publicly available.
Stop Guessing When to Stop Testing: Efficient Model Evaluation with Just Enough Data
Ofir Arviv | Kristjan Greenewald | Yotam Perlitz | Hadar Mulian | Michal Shmueli-Scheuer | Leshem Choshen
Findings of the Association for Computational Linguistics: ACL 2026
Ofir Arviv | Kristjan Greenewald | Yotam Perlitz | Hadar Mulian | Michal Shmueli-Scheuer | Leshem Choshen
Findings of the Association for Computational Linguistics: ACL 2026
The inherent rigidity of fixed-size benchmarks makes them an inefficient tool for model evaluation. Diverse evaluation objectives, including model ranking, model selection and testing throughout development, demand varying levels of statistical power. The mismatch between fixed sample sizes and these diverse needs results in either excessive computational cost or compromised reliability – a critical concern for model evaluation. To overcome these limitations, we call for adoption of sequential testing in our field. We provide an adaptive evaluation framework, that provides a principled way to navigate the trade-off between efficiency and reliability in model evaluation. Our framework combines the established statistical paradigm of sequential testing with stopping criteria tailored to common evaluation needs such as diminishing returns detection, and minimum detectable effect size. We demonstrate its ability to adaptively manage the efficiency-reliability trade-off on the Open VLM Leaderboard, including, for example, a 80% reduction in computational cost compared to fixed-size evaluation (with a 2.5-point CI width allowance) while maintaining statistical significance.
2025
Proceedings of the Fourth Workshop on Generation, Evaluation and Metrics (GEM²)
Ofir Arviv | Miruna Clinciu | Kaustubh Dhole | Rotem Dror | Sebastian Gehrmann | Eliya Habba | Itay Itzhak | Simon Mille | Yotam Perlitz | Enrico Santus | João Sedoc | Michal Shmueli Scheuer | Gabriel Stanovsky | Oyvind Tafjord
Proceedings of the Fourth Workshop on Generation, Evaluation and Metrics (GEM²)
Ofir Arviv | Miruna Clinciu | Kaustubh Dhole | Rotem Dror | Sebastian Gehrmann | Eliya Habba | Itay Itzhak | Simon Mille | Yotam Perlitz | Enrico Santus | João Sedoc | Michal Shmueli Scheuer | Gabriel Stanovsky | Oyvind Tafjord
Proceedings of the Fourth Workshop on Generation, Evaluation and Metrics (GEM²)
DOVE: A Large-Scale Multi-Dimensional Predictions Dataset Towards Meaningful LLM Evaluation
Eliya Habba | Ofir Arviv | Itay Itzhak | Yotam Perlitz | Elron Bandel | Leshem Choshen | Michal Shmueli-Scheuer | Gabriel Stanovsky
Findings of the Association for Computational Linguistics: ACL 2025
Eliya Habba | Ofir Arviv | Itay Itzhak | Yotam Perlitz | Elron Bandel | Leshem Choshen | Michal Shmueli-Scheuer | Gabriel Stanovsky
Findings of the Association for Computational Linguistics: ACL 2025
Recent work found that LLMs are sensitive to a wide range of arbitrary prompt dimensions, including the type of delimiters, answer enumerators, instruction wording, and more. This throws into question popular single-prompt evaluation practices. We present DOVE (Dataset Of Variation Evaluation) a large-scale dataset containing prompt perturbations of various evaluation benchmarks. In contrast to previous work, we examine LLM sensitivity from an holistic perspective, and assess the joint effects of perturbations along various dimensions, resulting in thousands of perturbations per instance. We evaluate several model families against DOVE, leading to several findings, including efficient methods for choosing well-performing prompts, observing that few-shot examples reduce sensitivity, and identifying instances which are inherently hard across all perturbations. DOVE consists of more than 250M prompt perturbations and model outputs, which we make publicly available to spur a community-wide effort toward meaningful, robust, and efficient evaluation. Browse the data, contribute, and more at: https://slab-nlp.github.io/DOVE
JuStRank: Benchmarking LLM Judges for System Ranking
Ariel Gera | Odellia Boni | Yotam Perlitz | Roy Bar-Haim | Lilach Eden | Asaf Yehudai
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Ariel Gera | Odellia Boni | Yotam Perlitz | Roy Bar-Haim | Lilach Eden | Asaf Yehudai
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Given the rapid progress of generative AI, there is a pressing need to systematically compare and choose between the numerous models and configurations available. The scale and versatility of such evaluations make the use of LLM-based judges a compelling solution for this challenge. Crucially, this approach requires first to validate the quality of the LLM judge itself. Previous work has focused on instance-based assessment of LLM judges, where a judge is evaluated over a set of responses, or response pairs, while being agnostic to their source systems. We argue that this setting overlooks critical factors affecting system-level ranking, such as a judge’s positive or negative bias towards certain systems. To address this gap, we conduct the first large-scale study of LLM judges as system rankers. System scores are generated by aggregating judgment scores over multiple system outputs, and the judge’s quality is assessed by comparing the resulting system ranking to a human-based ranking. Beyond overall judge assessment, our analysis provides a fine-grained characterization of judge behavior, including their decisiveness and bias.
2024
Holmes ⌕ A Benchmark to Assess the Linguistic Competence of Language Models
Andreas Waldis | Yotam Perlitz | Leshem Choshen | Yufang Hou | Iryna Gurevych
Transactions of the Association for Computational Linguistics, Volume 12
Andreas Waldis | Yotam Perlitz | Leshem Choshen | Yufang Hou | Iryna Gurevych
Transactions of the Association for Computational Linguistics, Volume 12
We introduce Holmes, a new benchmark designed to assess language models’ (LMs’) linguistic competence—their unconscious understanding of linguistic phenomena. Specifically, we use classifier-based probing to examine LMs’ internal representations regarding distinct linguistic phenomena (e.g., part-of-speech tagging). As a result, we meet recent calls to disentangle LMs’ linguistic competence from other cognitive abilities, such as following instructions in prompting-based evaluations. Composing Holmes, we review over 270 probing studies and include more than 200 datasets to assess syntax, morphology, semantics, reasoning, and discourse phenomena. Analyzing over 50 LMs reveals that, aligned with known trends, their linguistic competence correlates with model size. However, surprisingly, model architecture and instruction tuning also significantly influence performance, particularly in morphology and syntax. Finally, we propose FlashHolmes, a streamlined version that reduces the computation load while maintaining high-ranking precision.
Efficient Benchmarking (of Language Models)
Yotam Perlitz | Elron Bandel | Ariel Gera | Ofir Arviv | Liat Ein-Dor | Eyal Shnarch | Noam Slonim | Michal Shmueli-Scheuer | Leshem Choshen
Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
Yotam Perlitz | Elron Bandel | Ariel Gera | Ofir Arviv | Liat Ein-Dor | Eyal Shnarch | Noam Slonim | Michal Shmueli-Scheuer | Leshem Choshen
Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
The increasing versatility of language models (LMs) has given rise to a new class of benchmarks that comprehensively assess a broad range of capabilities. Such benchmarks are associated with massive computational costs, extending to thousands of GPU hours per model. However, the efficiency aspect of these evaluation efforts had raised little discussion in the literature.In this work, we present the problem of Efficient Benchmarking, namely, intelligently reducing the computation costs of LM evaluation without compromising reliability. Using the HELM benchmark as a test case, we investigate how different benchmark design choices affect the computation-reliability trade-off. We propose to evaluate the reliability of such decisions, by using a new measure – Decision Impact on Reliability, DIoR for short.We find, for example, that a benchmark leader may change by merely removing a low-ranked model from the benchmark, and observe that a correct benchmark ranking can be obtained by considering only a fraction of the evaluation examples.Based on our findings, we outline a set of concrete recommendations for efficient benchmark design and utilization practices. To take a step further, we use our findings to propose an evaluation algorithm, that, when applied to the HELM benchmark, leads to dramatic cost savings with minimal loss of benchmark reliability, often reducing computation by x100 or more.
Unitxt: Flexible, Shareable and Reusable Data Preparation and Evaluation for Generative AI
Elron Bandel | Yotam Perlitz | Elad Venezian | Roni Friedman | Ofir Arviv | Matan Orbach | Shachar Don-Yehiya | Dafna Sheinwald | Ariel Gera | Leshem Choshen | Michal Shmueli-Scheuer | Yoav Katz
Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 3: System Demonstrations)
Elron Bandel | Yotam Perlitz | Elad Venezian | Roni Friedman | Ofir Arviv | Matan Orbach | Shachar Don-Yehiya | Dafna Sheinwald | Ariel Gera | Leshem Choshen | Michal Shmueli-Scheuer | Yoav Katz
Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 3: System Demonstrations)
In the dynamic landscape of generative NLP, traditional text processing pipelines limit research flexibility and reproducibility, as they are tailored to specific dataset, task, and model combinations. The escalating complexity, involving system prompts, model-specific formats, instructions, and more, calls for a shift to a structured, modular, and customizable solution.Addressing this need, we present Unitxt, an innovative library for customizable textual data preparation and evaluation tailored to generative language models. Unitxt natively integrates with common libraries like HuggingFace and LM-eval-harness and deconstructs processing flows into modular components, enabling easy customization and sharing between practitioners. These components encompass model-specific formats, task prompts, and many other comprehensive dataset processing definitions. The Unitxt Catalog centralizes these components, fostering collaboration and exploration in modern textual data workflows. Beyond being a tool, Unitxt is a community-driven platform, empowering users to build, share, and advance their pipelines collaboratively. Join the Unitxt community at https://github.com/IBM/unitxt
Navigating the Modern Evaluation Landscape: Considerations in Benchmarks and Frameworks for Large Language Models (LLMs)
Leshem Choshen | Ariel Gera | Yotam Perlitz | Michal Shmueli-Scheuer | Gabriel Stanovsky
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024): Tutorial Summaries
Leshem Choshen | Ariel Gera | Yotam Perlitz | Michal Shmueli-Scheuer | Gabriel Stanovsky
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024): Tutorial Summaries
General-Purpose Language Models have changed the world of Natural Language Processing, if not the world itself. The evaluation of such versatile models, while supposedly similar to evaluation of generation models before them, in fact presents a host of new evaluation challenges and opportunities. In this Tutorial, we will start from the building blocks of evaluation. The tutorial welcomes people from diverse backgrounds and assumes little familiarity with metrics, datasets, prompts and benchmarks. It will lay the foundations and explain the basics and their importance, while touching on the major points and breakthroughs of the recent era of evaluation. It will also compare traditional evaluation methods – which are still widely used – to newly developed methods. We will contrast new to old approaches, from evaluating on many-task benchmarks rather than on dedicated datasets to efficiency constraints, and from testing stability and prompts on in-context learning to using the models themselves as evaluation metrics. Finally, the tutorial will cover practical issues, ranging from reviewing widely-used benchmarks and prompt banks to efficient evaluation.
2023
Active Learning for Natural Language Generation
Yotam Perlitz | Ariel Gera | Michal Shmueli-Scheuer | Dafna Sheinwald | Noam Slonim | Liat Ein-Dor
Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing
Yotam Perlitz | Ariel Gera | Michal Shmueli-Scheuer | Dafna Sheinwald | Noam Slonim | Liat Ein-Dor
Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing
The field of Natural Language Generation (NLG) suffers from a severe shortage of labeled data due to the extremely expensive and time-consuming process involved in manual annotation. A natural approach for coping with this problem is active learning (AL), a well-known machine learning technique for improving annotation efficiency by selectively choosing the most informative examples to label. However, while AL has been well-researched in the context of text classification, its application to NLG remains largely unexplored. In this paper, we present a first systematic study of active learning for NLG, considering a diverse set of tasks and multiple leading selection strategies, and harnessing a strong instruction-tuned model. Our results indicate that the performance of existing AL strategies is inconsistent, surpassing the baseline of random example selection in some cases but not in others. We highlight some notable differences between the classification and generation scenarios, and analyze the selection behaviors of existing AL strategies. Our findings motivate exploring novel approaches for applying AL to generation tasks.
2022
Zero-Shot Text Classification with Self-Training
Ariel Gera | Alon Halfon | Eyal Shnarch | Yotam Perlitz | Liat Ein-Dor | Noam Slonim
Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing
Ariel Gera | Alon Halfon | Eyal Shnarch | Yotam Perlitz | Liat Ein-Dor | Noam Slonim
Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing
Recent advances in large pretrained language models have increased attention to zero-shot text classification. In particular, models finetuned on natural language inference datasets have been widely adopted as zero-shot classifiers due to their promising results and off-the-shelf availability. However, the fact that such models are unfamiliar with the target task can lead to instability and performance issues. We propose a plug-and-play method to bridge this gap using a simple self-training approach, requiring only the class names along with an unlabeled dataset, and without the need for domain expertise or trial and error. We show that fine-tuning the zero-shot classifier on its most confident predictions leads to significant performance gains across a wide range of text classification tasks, presumably since self-training adapts the zero-shot model to the task at hand.
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- Michal Shmueli-Scheuer 8
- Leshem Choshen 7
- Ariel Gera 7
- Ofir Arviv 5
- Elron Bandel 4
- Liat Ein Dor 3
- Eyal Shnarch 3
- Noam Slonim 3
- Gabriel Stanovsky 3
- Eliya Habba 2
- Itay Itzhak 2
- Dafna Sheinwald 2
- Asaf Yehudai 2
- Shir Ashury-Tahan 1
- Roy Bar-Haim 1
- Odellia Boni 1
- Rajmohan C 1
- Miruna Clinciu 1
- Kaustubh Dhole 1
- Shachar Don-Yehiya 1
- Rotem Dror 1
- Lilach Eden 1
- Roni Friedman 1
- Sebastian Gehrmann 1
- Kristjan Greenewald 1
- Iryna Gurevych 1
- Alon Halfon 1
- Yufang Hou 1
- Yoav Katz 1
- Percy Liang 1
- Yifan Mai 1
- Simon Mille 1
- Hadar Mulian 1
- Matan Orbach 1
- Enrico Santus 1
- João Sedoc 1
- Oyvind Tafjord 1
- Elad Venezian 1
- Andreas Waldis 1