Gantry · dataset evaluation · 13 September 2026

On the same task, the scripted episodes all end in a hold and the human ones almost never do

Written for Denis Garagic at Palladyne AI. The dataset read here is lerobot/aloha_sim_insertion_scripted. It is not Palladyne AI's data, and it is on this page because peg insertion, the canonical industrial manipulation task, released twice by the same group, once from a human operator and once from a script.

The same group released peg insertion twice, same task string, same robot, same 50 fps, fifty episodes each. The scripted release has a trailing hold on 100% of episodes, 86% of them ten frames or longer. The human release has one on 6%, and the longest anywhere is a single frame. Both are fixed length, 400 frames scripted against 500 human, so the difference is not episode length. It is that a script stops commanding and a person does not.

scripted, any hold
100%
50 episodes, 400 frames each
human, any hold
6%
50 episodes, 500 frames each
scripted, ten frames or more
86%
longest 0.42s
human, longest hold
0.02s
1 frame

The release, as it actually is

Read from lerobot/aloha_sim_insertion_scripted. Where a figure came from the release metadata rather than the frames, the mode line below says so.

property value
episodes 50
frames 20,000
frame rate 50 fps
robot aloha
action dimensions 14
cameras 1
distinct task strings 1
episode length, shortest 400 frames
episode length, median 400 frames
episode length, longest 400 frames

And the one it is compared against

lerobot/aloha_sim_insertion_human.

property value
episodes 50
frames 25,000
frame rate 50 fps
robot aloha
action dimensions 14
cameras 1
distinct task strings 1
episode length, shortest 500 frames
episode length, median 500 frames
episode length, longest 500 frames

Measurement mode, frame level, every row read.

The result across eight corpora

The trailing hold tracks how the data was produced, not what the task was

A trailing hold is the number of frames at the end of an episode during which the commanded action does not change by more than 1e-4 on any component. Seconds come from the frame rate each release declares. Every corpus below was read the same way by the same code.

public corpus how it was produced episodes any trailing hold ten frames or more longest
lerobot/aloha_sim_insertion_scripted scripted sim 50 100.0% 86.0% 21 frames , 0.42s
RajatDandekar/so101_bimanual_napkin_fold real bimanual teleop 65 95.4% 75.4% 130 frames , 4.33s
weblucas/sponge_ball_2_yellow_tray_lerobot real single arm teleop 30 26.7% 6.7% 21 frames , 0.70s
lerobot/aloha_sim_insertion_human sim human teleop 50 6.0% 0.0% 1 frames , 0.02s
lerobot/ucsd_pick_and_place_dataset sim, fixed window 1,355 0.1% 0.0% 2 frames , 0.40s
RajatDandekar/eval_so101_pi0_bimanual_napkin_fold policy rollouts 6 0.0% 0.0% 0 frames , 0.00s

The ordering is the finding. A script stops commanding when it is done and the last rows repeat. A person keeps making small corrections, so a short take ends clean while a long bimanual take ends with the operator holding the fold in place. A policy rollout ends the moment the episode is cut. If somebody quotes you a single defect rate for idle frames across a mixed corpus, that number is averaging four different things.

How to check this without taking our word

Each corpus is a meta directory plus one or more parquet files. Read data/chunk-000/file-000.parquet, group rows by the episode ranges in meta/episodes, and count trailing rows where the action vector does not change. No credentials and no download beyond the frame data itself.

The wider record

What else has been graded

Thirty eight public robot datasets, one at a time. Each report measures one property across every episode, removes the part that scores worst, and retrains on what is left. The corpus figures and the cuts are computed from the releases. The lift column on the results page is read from each report's fine tune table rather than from a training run, and that page says so.

datasets graded
38
across 31 organisations
episodes examined
2,212,712
every one scored
episodes removed
123,143
5.6% of the total
rollouts graded
30,020
234 tasks

The one result measured on physical hardware is Stera-10M. Two arms on a four arm SO-ARM101 bench, identical per task fine tunes, 127 unpaired rollouts per cell, and the only difference between the arms is whether the human video pre-training stage happened.

Baseline
21.9%
no human video training. CI 18.8 to 25.3 · n=635
With ego stage
36.9%
after human video. CI 33.2 to 40.7 · n=635
Pooled lift
+15.0 pp
five tasks together. 95% range +10.0 to +19.8
Bench rollouts
1,270
5 tasks · 2 arms · 127 each

What grading Palladyne AI's own corpus would add

Everything above is a public release. The same four steps run on your data, and the first three cost nothing.

A few hundred episodes under whatever terms you want is enough for the first three.