MolmoSpaces-CommonSense: Evaluating Commonsense in Robotic Manipulation Policies
Organizations: Paul G. Allen School of Computer Science & Engineering, University of Washington, Seattle, WA, USA · Allen Institute for AI (Ai2), Seattle, WA, USA · National University of Singapore, Singapore
Abstract
Real-world robotic manipulation requires reasoning about cluttered scenes, partially observable or hidden objects, and semantically appropriate actions, in addition to low-level execution within those scenes. However, existing simulation benchmarks primarily test the latter and remain dominated by comparatively clean environments with limited clutter and narrowly scoped task structure, leaving many forms of commonsense reasoning untested. We address this by introducing a taxonomy of reasoning processes for robotic manipulation grounded in developmental cognitive science. We operationalize this taxonomy through a new benchmark of robot tasks, MolmoSpaces-CommonSense, that requires reasoning about occlusion, containment, support relations, semantically correct grasp points, spatial affordances, and hidden objects. These evaluations require policies not only to recognize relevant scene structure but also to execute correct actions in them. We evaluate several zero-shot generalist manipulation policies. Across model types and architectures, we observe consistent failures in commonsense reasoning: success rates in cluttered scenes drop by over 50% as distractors increase, policies act on incorrect objects in cluttered settings 30% of the time, and affordance-sensitive grasping remains unreliable even with highly specific language prompts, with correct object part selection happening only about 50% of the time. Further, VLM-based success estimation struggles to reliably evaluate rollouts in these settings, suggesting that the challenge extends beyond control to the broader perception-reasoning-action stack. Our results suggest that existing benchmarks may substantially overestimate zero-shot real-world readiness. Code and policy leaderboard link at https://github.com/allenai/molmospaces.
Figures & tables
| Task | Category | Subcategory | # Envs | Success Condition |
| Pick with Occlusion | Phys. Reas. | Occlusion | 1000 | Target object lifted |
| Pick with Covering | Phys. Reas. | Covering | 1000 | Target object lifted |
| Pick with Containment | Phys. Reas. | Containment | 500 | Target object lifted |
| Pack with Occlusion | Phys. Reas. | Occlusion | 1000 | All objects in receptacle |
| Pack with Covering | Phys. Reas. | Covering | 1000 | All objects in receptacle |
| Pick with Affordance | Affordances | Grasping | 500 | Lifted + correct grasp pose |
| Physical Reasoning | Affordance | Obj. Perm. | ||||||
| Policy | Pick w/ Occlusion | Pick w/ Covering | Pick w/ Containment | Pack w/ Occlusion | Pack w/ Covering | Pick w/ Affordance | Stack w/ Affordance | Pick w/ Obj. Permanence |
| -FAST | ||||||||
| DreamZero | ||||||||
| MolmoAct2 | ||||||||
| Evaluator | DreamZero | MolmoAct2 | Mean | |
| Molmo2 | 27.9 | 37.4 | 19.4 | 28.2 |
| Qwen3.5-122B-A10B | 44.6 | 46.1 | 44.8 | 45.2 |
| Gemini 3.1 | 46.6 | 63.1 | 43.8 | 51.2 |
| Gemini Robotics-ER 1.6 | 50.5 | 51.0 | 53.2 | 51.6 |
| MolmoAct2 | DreamZero | CAP rand | CAP mem | ||
| SR (%) | 0.00 0.37 | 0.30 0.57 | 0.30 0.57 | 17.30 2.47 | 28.20 2.87 |
| # Nearby Objects | Episodes | % (95% CI) |
| 0 | 54 | 13.6 (10.6–17.4) |
| 1 | 109 | 27.5 (23.4–32.1) |
| 2 | 88 | 22.2 (18.4–26.6) |
| 3 | 76 | 19.2 (15.6–23.4) |
| 4 | 32 | 8.1 (5.8–11.2) |
| 37 | 9.3 (6.9–12.6) |
| Task | Horizon (Policy Steps) |
| Pick with Occlusion | 300 |
| Pick with Covering | 300 |
| Pick with Containment | 500 |
| Pack with Occlusion | 1500 |
| Pack with Covering | 1500 |
| Pick with Affordance | 300 |
| Parameter | MolmoAct2 | , -FAST, | DreamZero | TiPToP |
| Policy Type | Learned | Learned | Learned | TAMP (Planner) |
| Finetuning | DROID | DROID | DROID | N/A |
| Output Format | Joint Position | Joint Position | Joint Position | Joint Position |
| Policy | 66 ms / 15.15 Hz | 66 ms / 15.15 Hz | 66 ms / 15.15 Hz | 66 ms / 15.15 Hz |
| Actions Executed per Chunk | 8 | 8 | 24 | N/A, Open-Loop |
| Cameras | Wrist + Exo | Wrist + Exo | Wrist + Exo | Wrist + Exo, + Depth |
| Evaluator | DreamZero | MolmoAct2 | Mean | |
| Gemini 3.1 (high) | 45.1 | 52.9 | 45.8 | 47.9 |
| Gemini 3.1 (low) | 46.6 | 63.1 | 43.8 | 51.2 |
| Gemini 3.1 (medium) | 44.6 | 53.9 | 42.8 | 47.1 |
| Gemini Robotics-ER 1.6 (high) | 51.0 | 50.5 | 52.2 | 51.2 |
| Gemini Robotics-ER 1.6 (low) | 50.5 | 51.0 | 53.2 | 51.6 |
| GPT-5.4 (high) | 45.1 | 46.1 | 46.8 | 46.0 |
| True Pred | No Grasp | Wrong | Success | Clutter | Grasping | Total |
| Attempt | Object | Success | Collision | Failure | ||
| No Grasp Attempt | 87 | 59 | 22 | 2 | 7 | 177 |
| Wrong Object | 15 | 126 | 10 | 3 | 3 | 157 |
| Success | 1 | 8 | 77 | 1 | 5 | 92 |
| Clutter Collision | 0 | 15 | 10 | 1 | 0 | 26 |
| Grasping Failure | 11 | 49 | 74 | 3 | 22 | 159 |
| True Pred | No Grasp | Wrong | Success | Clutter | Grasping | Total |
| Attempt | Object | Success | Collision | Failure | ||
| No Grasp Attempt | 98 | 43 | 0 | 1 | 35 | 177 |
| Wrong Object | 31 | 104 | 1 | 1 | 20 | 157 |
| Success | 7 | 9 | 12 | 2 | 62 | 92 |
| Clutter Collision | 2 | 10 | 0 | 3 | 11 | 26 |
| Grasping Failure | 23 | 25 | 8 | 5 | 98 | 159 |
Robotic Manipulation
Robotic manipulation studies how robots perceive, plan, and control physical interactions to grasp, move, assemble, and use objects.
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