Learning Counterfactual World Models for Embodied Reasoning under Partial Observability
Organizations: Harvard University
Abstract
World models promise a general route to embodied intelligence: learn predictive dynamics once, then reason, plan, and act with them. Increasingly, the representations beneath such models are pretrained on large-scale video, interaction, and multimodal corpora, which raises a question prediction quality alone cannot answer: when is a learned representation actually actionable? We identify a failure mode we call counterfactual collapse: a model predicts visually plausible futures while failing to distinguish interventions with different behavioral consequences. This arises whenever a representation is optimized for perceptual similarity rather than intervention structure, which is precisely the objective under which most large-scale pretrained encoders are learned. We introduce Counterfactual Latent World Models (CLWM), which combine a recurrent belief-state encoder, action-conditioned latent dynamics, and a contrastive counterfactual objective that separates futures induced by distinct interventions even when their observations look alike. Across occluded manipulation, aliased navigation, and long-horizon manipulation, CLWM improves planning success over the strongest baseline (65.1% 74.6% on Occluded Push and 67.3% 78.9% on Aliased Maze) and reduces exploitative planning failures (18.4% 9.7% on Deferred Kitchen), with ablations attributing the gains to hard counterfactual negatives, especially perceptual-alias negatives. Finally, our counterfactual separability metric, which tracks planning success across the five baseline model classes (), is representation-agnostic: given intervention-outcome labels, it can audit any encoder, pretrained or trained from scratch, before a planner trusts it. We do not yet measure it on large-scale pretrained encoders. Here we establish the metric and its relationship to planning success for world models trained from scratch.
Figures & tables
| Method | Occluded Push | Aliased Maze | Deferred Kitchen | |||
|---|---|---|---|---|---|---|
| Success | CFS | Success | CFS | Return | Exploit | |
| RSSM-Recon | 47.8 2.1 | 0.61 | 52.4 1.8 | 0.58 | 43.2 2.7 | 31.5 |
| Reward-aware RSSM | 55.6 1.9 | 0.66 | 58.1 2.0 | 0.63 | 51.7 2.4 | 24.8 |
| CPC-RSSM | 58.4 2.4 | 0.70 | 61.5 1.7 | 0.68 | 53.9 2.1 | 22.7 |
| Dreamer-style | 62.9 1.6 | 0.69 | 65.7 1.9 | 0.67 | 59.4 1.8 | 20.9 |
| TD-MPC-style | 65.1 1.6 | 0.71 | 67.3 1.5 | 0.70 | 62.8 2.0 | 18.4 |
| Variant | Push Succ. | Maze Succ. | Avg. CFS | Kitchen Exploit |
|---|---|---|---|---|
| Full CLWM | 74.6 | 78.9 | 0.85 | 9.7 |
| No same-belief negatives | 70.2 | 72.4 | 0.79 | 13.6 |
| No perceptual-alias negatives | 67.5 | 69.1 | 0.74 | 16.8 |
| No value-disagreement negatives | 71.3 | 74.0 | 0.81 | 12.9 |
| No outcome head | 70.8 | 73.5 | 0.80 | 13.2 |
| Random negatives only | 68.1 | 70.6 | 0.76 | 15.4 |
Appendix figures & tables2 assets
Supplementary material from the paper’s appendix.
Appendix
| Setting | Value |
|---|---|
| Seeds & statistics | 5 seeds (0–4); is the standard error of the mean over seeds |
| Belief / latent dimension | 200 / 32 |
| Planner | MPC with candidate sequences, horizon |
| Counterfactual rollout horizon | |
| Contrastive temperature | |
| Loss weights | , , (with free bits), , |
| Field | Value |
|---|---|
| Counterfactual branching | intervention sequences per anchor; branch source: 50% policy rollouts, 25% random shooting, 25% replay trajectories |
| Negative mining | perceptual-alias similarity via LPIPS on image patches over a 5-step window; 16 negatives per anchor; outcome distance threshold |
| Outcome descriptors | Occluded Push: hidden-object pose relative to goal, success threshold 0.05 m; Aliased Maze: discrete topological cell index (0–63); Deferred Kitchen: binary feasibility vector over later subtasks (e.g., stove on, kettle filled) |
| Simulators | Occluded Push: MuJoCo (MJX) v1.2.1; Aliased Maze: Gymnasium-based grid world v0.1.0; Deferred Kitchen: RoboSuite v2.0 (adapted) |
| Encoder | 4-layer CNN (32/64/128/256 channels, kernel 3, stride 2, ReLU) followed by a fully connected layer to 256 units; proprioceptive/tactile branch: 2-layer MLP (128, 64), concatenated |
| Decoder | transposed CNN mirroring the encoder |
Embodied World Models
Embodied world models predict how environments change under an agent’s actions to support planning, learning, simulation, and control.
See all 164 papers