UIST Supplementary

At most venues supplementary material is an appendix annex. At UIST the central supplementary object is the video figure, and it is closer to a second first-page than to an attachment: reviewers at a venue built on demo culture watch it early, form their belief about whether the system is real, and read the paper through that belief. The 2026 Author Guide calls it optional but highly encouraged; for any paper whose contribution moves, responds, or renders, treat "optional" as theoretical.

The 2026 video spec (verified 2026-07-08)

Captions/subtitles make the video robust to reviewers watching without audio and prefigure the accessibility work required at camera-ready (see uist-camera-ready).

Script the video around claims, not features

Build the shot list from the paper's contribution list — the video is the visual twin of uist-experiments' claim-evidence audit:

0:00-0:15  Problem in one shot: the interaction that is impossible/painful today
0:15-0:45  The artifact working, uncut, on the core capability (claim C1)
0:45-1:45  C2..Cn each demonstrated in one continuous take
1:45-2:30  Breadth: 3-4 application vignettes, a few seconds each
2:30-3:00  Envelope honesty: one edge condition, then the closing capability shot

Production rules that pay at review time:

• Real time by default. Label any speed change on screen. Nothing erodes trust faster than suspecting a cut hides recognition latency.
• Uncut interaction loops for the core claim: input and response in the same frame — screen-plus-hands, or picture-in-picture.
• No staged reactions or marketing gloss; reviewers are builders, and polish that outruns the paper's measurements reads as concealment.
• Consistency audit: every capability shown must be measured or demonstrated in the paper; every headline claim in the paper should be visible in the video.

Narration and captions

The soundtrack is argument, not atmosphere:

• Narrate what the viewer is seeing and why it is hard, in the paper's vocabulary — the video and the PDF should share their key terms so reviewers can cross-reference without translation.
• One sentence of narration per shot; silence over a working demo is stronger than filler ("as you can see, the system works well" convinces no one).
• On-screen labels for condition changes ("2× speed", "different user", "outdoor lighting") — reviewers treat unlabeled cuts as concealment.
• Captions verbatim from narration, timed to shots; they are how the video reads in a quiet review session and they seed the accessibility work that camera-ready requires anyway.
• No music under narration, no title-card branding that could hint at a lab's house style.

Editing checklist before the spec check

[ ] every cut between input and response is labeled or absent
[ ] each claim shot runs uncut for at least one full interaction loop
[ ] condition labels present for speed/user/environment changes
[ ] captions complete, spell-checked, synchronized
[ ] first 20 seconds show the artifact working (reviewers may not finish)
[ ] final frame is the capability, not a logo

Anonymizing moving pictures

Video leaks identity through channels PDFs do not have:

• Frames: faces, badges, lab posters, whiteboards, distinctive rooms, license plates through windows.
• Audio: narrators saying "at our lab in...", recognizable voices; re-record or synthesize narration if needed.
• Overlays and assets: watermarks, usernames in menu bars, OS accounts, project names in window titles.
• Metadata: camera serials and GPS in the container.

# Spec + metadata check on the exact upload file
ffprobe -v error -show_entries format=duration,size:stream=codec_name,width,height video.mp4
ffmpeg -i video.mp4 -map_metadata -1 -c copy video_clean.mp4   # strip container metadata

Beyond the video: what else to ship

• Anonymized overlap copy — required in 2026 when a prior submission of yours overlaps heavily (see uist-submission); this is a UIST-specific obligation.
• Code, firmware, and design files — reviewed as evidence of reality; package them runnable-in-five-minutes (see uist-artifact-evaluation).
• Extended results — full benchmark grids, study instruments, codebooks; but anything decision-critical belongs in the PDF's appendix, since supplementary reading is at reviewer discretion.
• A manifest — one README listing every file and which paper section it backs; unlabeled archives simply do not get opened.

Scheduling reality

Video production consumes the same final two weeks as paper polish and cannot start before the system is stable. Book the capture rig, the edit pass, the caption pass, and the compression/verification pass as calendar items at feature freeze (uist-workflow), and dry-run the export pipeline early — render failures at 2 am AoE are a recurring UIST deadline story.

Output format

[Video status] scripted / shot / edited / spec-verified / anonymized
[Claim coverage] video shows <k>/<n> contribution claims; gaps: <list>
[Spec check] duration · resolution · codec · captions · metadata
[Supplement set] <files + the section each supports>
[Risk] <the single most likely late failure in the pipeline>