Are We Measuring Anticipation? Auditing Privileged Information in Procedural Video Evaluation
Organizations: University of Exeter Exeter, United Kingdom
Abstract
Benchmark scores license claims about the capabilities being evaluated. We audit the inference licensed by an evaluation protocol, rather than the predictive model alone. Using procedural action anticipation as a controlled case study, we study a broader evaluation-validity failure mode: a protocol can remain temporally causal and free of classical target leakage while still supplying a privileged intermediate representation. The failure is not merely optimistic accuracy, but a mismatch between the capability claimed and the construct actually measured. On Breakfast, matched recognizer-history and GT-history regimes score 30.3% and 62.3% (Delta_PH(R_BA) = +32.0, 95% Student-t interval [+24.1, +39.8]). A fixed-checkpoint 2 x 2 intervention isolates a +14.6-point test-time oracle contrast; a matched no-video provenance probe yields a +26.8-point gap; and a boundary-independent query/history control retains a +19.4-point gap. We refer to this discrepancy as a privileged-information gap, defined relative to a specified non-oracle recovery pipeline, and propose a reusable four-condition audit. Across five evaluation settings the gap is heterogeneous; a standard 50 Salads long-term-anticipation re-implementation provides cautious support beyond the audit-specific next-action construction.
Figures & tables
| Condition | Act.@1 | Act.@5 | Verb@1 |
|---|---|---|---|
| Video only | |||
| Recognizer history, boundary-free | — | — | |
| Recognizer history, boundary-aware | |||
| GT transcript (oracle) | |||
| Context-only (oracle context) |
| Comparison | Non-oracle | Oracle | Gap [95% CI] | Interpretation |
|---|---|---|---|---|
| Matched information regimes | Primary estimator-relative protocol-level audit gap. | |||
| Fixed checkpoint | Test-time oracle substitution with weights fixed. | |||
| No-video context | Separates oracle provenance from context predictability. | |||
| Boundary-independent query/history | Removes annotated boundaries from query scheduling and recovered history. |
| Dataset | Window-rec. | BFR | BA | GT |
|---|---|---|---|---|
| Breakfast | ||||
| 50 Salads | ||||
| GTEA |
| Setting | Recognizer | GT | 95% split-level interval | Scope | |
|---|---|---|---|---|---|
| Breakfast | primary audit | ||||
| 50 Salads | next-action audit setting | ||||
| GTEA † | diagnostic next-action | ||||
| Assembly101 † | diagnostic next-action | ||||
| EPIC-100 †‡ | — | diagnostic, |
| 95% CI (per video) | ||||
|---|---|---|---|---|
| 95% CI (per split) |
| Evidence | What it addresses |
|---|---|
| Fixed checkpoint: | Not only a consequence of training under cleaner history. |
| Matched regimes: | Primary estimator-relative audit gap. |
| No-video provenance: | Not merely “context is predictive.” |
| Boundary-independent: | Annotated query/history boundaries are not sufficient. |
| 50 Salads standard LTA | Supporting evidence beyond audit-specific next-action construction. |
Appendix figures & tables17 assets
Supplementary material from the paper’s appendix.
Appendix
| Work | Observed-past source | Relevance |
|---|---|---|
| Uncertainty-aware anticipation Abu Farha and Gall [2019] | Clean/GT and recognized observations | Separates clean and inferred observed actions. |
| Cycle-consistent anticipation Abu Farha et al. [2020] | Visual features | Motivates direct video-to-future prediction rather than fixed transcripts. |
| AntGPT Zhao et al. [2024] | Symbolic actions derived from observations | Uses semantic action sequences as context. |
| AAG Benavent-Lledo et al. [2025] | GT, recognizer-, or VLM-derived history | Makes history provenance a first-order modeling choice. |
| Condition | Act.@1 | Act.@5 | Verb@1 |
|---|---|---|---|
| Video only | |||
| Recognizer history, boundary-free | — | — | |
| Recognizer history, boundary-aware | |||
| GT transcript (oracle) | |||
| Context-only oracle probe |
| Train history | Test: recognizer | Test: GT |
|---|---|---|
| Recognizer | ||
| GT oracle |
| Condition | Act.@1 (%) |
|---|---|
| Video only | |
| Recognizer history | |
| GT history (oracle) | |
| 95% Student- interval |
| Dataset | Window-recog. | BFR | BA | Drop | GT |
|---|---|---|---|---|---|
| Breakfast | |||||
| 50 Salads | |||||
| GTEA |
| History length | 0 | 1 | 2 | 4 | 8 |
|---|---|---|---|---|---|
| GT history | 23.8 | 51.0 | 61.9 | 60.0 | 60.6 |
| Recognizer history | 23.8 | 27.4 | 29.2 | 32.2 | 31.0 |
| Dataset | Backbone | #cls | Video | Rec.(BA) | Rec.(BFR) | GT | ||
|---|---|---|---|---|---|---|---|---|
| Breakfast | I3D | 47 | 21.7 | |||||
| 50 Salads | I3D | 19 | 40.7 | |||||
| GTEA † | I3D | 11 | 67.3 | |||||
| Assembly101 † | TSM | 86 | 21.3 | — | — | |||
| EPIC-100 †‡ | TSN | 331 | 14.4 | 14.7 | — | 15.0 | — |
| Observed history | ||||
|---|---|---|---|---|
| Recognizer | 7.6 | 6.2 | 4.9 | 4.1 |
| GT transcript | 9.5 | 11.3 | 8.7 | 6.5 |
| +2.0 | +5.2 | +3.8 | +2.4 | |
| 95% CI (per video) | ||||
| 95% CI (per split) |
| Condition | |||||
|---|---|---|---|---|---|
| Video only | 25.4 | 23.9 | 21.7 | 19.8 | 20.6 |
| Recognizer history | 35.1 | 29.5 | 24.4 | 21.8 | 22.0 |
| GT history | 61.0 | 46.6 | 38.1 | 33.3 | 34.0 |
| +25.9 | +17.1 | +13.7 | +11.5 | +12.1 | |
| 95% interval |
| Predictor | Breakfast | 50 Salads | GTEA |
|---|---|---|---|
| Majority | |||
| Bigram | |||
| Latest action only | |||
| Completed-action set | |||
| Full ordered history | |||
| Gain from latest action | +41.7 | +53.0 | +47.2 |
| Probe input | Act.@1 (%) |
|---|---|
| History only | |
| State only | |
| History + state |
| Probe context | Act.@1 (%) |
|---|---|
| Recognizer context | |
| GT context | |
| Privileged-context gap | |
| 95% Student- interval |
| Architecture | Video | Rec. | GT | CI/status | ||
|---|---|---|---|---|---|---|
| Transformer-fusion | 21.7 | 30.3 | 62.3 | +32.0 | 4 | |
| TCN | 24.9 | 32.2 | 59.3 | +27.1 | 4 | |
| GRU | 27.8 | 37.0 | 61.7 | +24.8 | 4 | |
| SSM | 24.4 | 29.4 | 57.6 | +28.2 | 2 | robustness |
| Causal LM | 21.6 | 32.1 | 57.6 | +25.6 | 2 | robustness |
| Diffusion | 18.4 | 28.8 | 57.8 | +28.9 | 2 | robustness |
| Target-class frequency | |||
|---|---|---|---|
| Bin | rarest | middle | commonest |
| Mean train count | 102.6 | 192.6 | 411.8 |
| Act.@1 | 50.2 | 62.5 | 77.5 |
| Transition probability | |||
| Bin | rare | medium | frequent |
| Mean probability | 0.028 | 0.306 | 0.782 |
| GT history | Recognizer history | |
| Full model | 63.4 | 31.7 |
| Zero video | ||
| Zero history | ||
| Zero state | ||
| grad input video | 57.3% | 79.5% |
| grad input history | 36.0% | 17.8% |
Benchmark Auditing
Benchmark auditing checks whether evaluation datasets, metrics, and infrastructure measure the capabilities and risks they claim to assess.
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