# What Do Current Systematic Generalization Tasks Miss? A Reasoning-Centered Analysis

arXiv: https://arxiv.org/abs/2609.19212 · HTML: https://mlsanity.com/paper/2609.19212/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Builds on 21 of its 33 references that are in the map.
- First posted on arXiv 16 Sep 2026.

## Builds on (most cited first, 21 of 21)

- [Compositionality decomposed: how do neural networks generalise?](https://mlsanity.com/paper/1908.08351/) (2019)
- [COGS: A Compositional Generalization Challenge Based on Semantic Interpretation](https://mlsanity.com/paper/2010.05465/) (2020)
- [T2I-CompBench++: An Enhanced and Comprehensive Benchmark for Compositional Text-to-image Generation](https://mlsanity.com/paper/2307.06350/) (2023)
- [A Benchmark for Systematic Generalization in Grounded Language Understanding](https://mlsanity.com/paper/2003.05161/) (2020)
- [Speak-to-Structure: Evaluating LLMs in Open-domain Natural Language-Driven Molecule Generation](https://mlsanity.com/paper/2412.14642/) (2024)
- [ReCOGS: How Incidental Details of a Logical Form Overshadow an Evaluation of Semantic Interpretation](https://mlsanity.com/paper/2303.13716/) (2023)
- [ReaSCAN: Compositional Reasoning in Language Grounding](https://mlsanity.com/paper/2109.08994/) (2021)
- [Compositional Networks Enable Systematic Generalization for Grounded Language Understanding](https://mlsanity.com/paper/2008.02742/) (2020)
- [HIGHT: Hierarchical Graph Tokenization for Molecule-Language Alignment](https://mlsanity.com/paper/2406.14021/) (2024)
- [Does Safety Training of LLMs Generalize to Semantically Related Natural Prompts?](https://mlsanity.com/paper/2412.03235/) (2024)
- [Progressive Compositionality in Text-to-Image Generative Models](https://mlsanity.com/paper/2410.16719/) (2024)
- [When Can Transformers Ground and Compose: Insights from Compositional Generalization Benchmarks](https://mlsanity.com/paper/2210.12786/) (2022)
- [Baba Is AI: Break the Rules to Beat the Benchmark](https://mlsanity.com/paper/2407.13729/) (2024)
- [SAGE-Eval: Evaluating LLMs for Systematic Generalizations of Safety Facts](https://mlsanity.com/paper/2505.21828/) (2025)
- [VSC: Visual Search Compositional Text-to-Image Diffusion Model](https://mlsanity.com/paper/2505.01104/) (2025)
- [Analyzing the Inner Workings of Transformers in Compositional Generalization](https://mlsanity.com/paper/2502.15277/) (2025)
- [Compositional-ARC: Assessing Systematic Generalization in Abstract Spatial Reasoning](https://mlsanity.com/paper/2504.01445/) (2025)
- [Improved Compositional Generalization by Generating Demonstrations for Meta-Learning](https://mlsanity.com/paper/2305.13092/) (2023)
- [Reinforcement Learning for Compositional Generalization with Outcome-Level Optimization](https://mlsanity.com/paper/2605.04920/) (2026)
- [Do LLMs Truly Generalize in the Molecular Domain? A Perturbation-Based Analysis](https://mlsanity.com/paper/2607.01800/) (2026)
- [Rule-Compliant Visual Spatial Planning for Multimodal Large Language Models](https://mlsanity.com/paper/2608.20237/) (2026)

## Abstract (arXiv)

Systematic generalization, the ability to solve novel problems by recombining known atomic elements, is central to human intelligence but difficult to study rigorously under controlled settings. Existing studies therefore rely on simplifications such as elemental composition, productivity-based tests, and action-explicit goals, which make systematic generalization easier to study but omit some essential aspects of this capability. To characterize what these simplifications miss, we adopt a reasoning-centered lens and introduce TranSGrid, a testbed that brings deductive, inductive, and abductive reasoning together within a unified task. Experiments with seven Transformer models on 4,800 TranSGrid instances show that all models perform much worse on TranSGrid than on a held-out test set: the largest model solves 79.6% of the test set, but only 55.3% of TranSGrid and 15.8% of the hardest subset. The gap remains within the training length range, showing that productivity alone is not sufficient to evaluate systematic generalization. Additionally, we reintroduce the other two simplifications into TranSGrid: one variant limits interactions among action effects to approximate elemental composition (reducing the inductive demand); the other makes goals action-explicit (reducing the abductive one). In both, solve rates return to roughly the test set level, showing that either simplification alone is enough to reduce TranSGrid to an ordinary held-out test set. Together, our results show that existing tasks reduce either or both of the inductive and abductive demands of systematic generalization, and that comprehensively measuring this capability requires a task that involves all three forms of reasoning.
