| # Splits |
|
|
| The unit is the **scene**, never a frame: an episode's frames differ by one |
| click, so splitting them apart tests memorisation. |
|
|
| ## What is held out, and what it cost |
|
|
| A held-out split is not a dial. Its size is the footprint of the attribute, |
| because a valid "unseen X" claim needs *every* scene containing X out of |
| training — not only the scenes you want to test on. |
|
|
| | axis | held out | observations | asks | |
| | --- | --- | ---: | --- | |
| | `test_app` | `gnome-system-monitor` | 11,350 | an unseen *category* | |
| | | `pluma` | 15,733 | an unseen *instance* beside three seen text editors | |
| | | `xarchiver` | 15,221 | an unseen *instance* beside file-roller | |
| | `test_theme` | `quartz_night_nord` | 46,730 | unseen desktop chrome | |
| | `test_resolution` | `retina_2880x1800` | 69,213 | unseen scale and aspect ratio | |
|
|
| `eog` was a fourth candidate — the unseen category "image viewer". It is not |
| held out: it appears in 109,454 observations against 11,352 for |
| `gnome-system-monitor`, and both answer the same question. Dropping it returned |
| 94,326 observations to training and gave up no claim the design still makes. |
|
|
| `retina_2880x1800` is **not** the cheapest resolution — `uhd_3840x2160` is, at |
| 4.83% against 7.06%. UHD is the densest supervision in the corpus, with the |
| smallest text and the most elements per screen, and training needs it more than |
| the split does. Of the candidates that leave UHD in training, 2880×1800 is both |
| the cheapest and the sharper test: it is one of only two 16:10 resolutions, so |
| holding it out leaves training a single 16:10 scale. |
|
|
| ## Zero leakage, and how it is checked |
|
|
| Over the **union of applications across every frame of a scene**. One capture of |
| a scene can miss an application another capture of it saw; keying on a single |
| frame is exactly how three held-out applications leaked into train in an earlier |
| build. The union is taken over *publishable* frames only, since a frame the |
| release drops cannot leak — one scene turned on that distinction, where the |
| held-out application launched only in a copy that failed quality checks. |
|
|
| `scripts/verify_hf_release.py` re-checks this against the packed payload and |
| fails the release if any held-out attribute reaches `train`. |
|
|
| ## Scenes the finalized split never placed |
|
|
| `splits_v3.jsonl` covers the 1,067,799 state-train-eligible observations. This |
| release carries every *publishable* observation, 1,207,368, so 12,515 scenes |
| needed a split it never assigned. They get one from the same rules in the same |
| priority (`test_app`, then `test_theme`, then `test_resolution`, else `train`), |
| and every existing v3 assignment is preserved exactly — verified per split. |
|
|
| `val` and `test_id` are **never** enlarged. They are a finalized random sample; |
| growing them after the fact would change what a number measured against them |
| means. |
|
|
| ## Occlusion is a reporting axis, not a split |
|
|
| Holding out occluded scenes would remove the capability the corpus exists to |
| demonstrate. Report it as a degradation curve over `test_id` instead: |
|
|
| | occluded ratio | share of observations | |
| | --- | ---: | |
| | none | 2.3% | |
| | 0–10% | 15.6% | |
| | 10–25% | 27.5% | |
| | 25%+ | 54.6% | |
|
|
| Median 0.284, p90 0.743, p99 0.930. Window count is available as `n_windows` for |
| the same purpose. |
|
|
