Domain: Natural Science — Atmospheric Science
Target concept: Floc-like small droplet clouds form from nothing within the chamber, and the cloud clusters gradually accumulate at the bottom.

Video generation prompt: A transparent plastic chamber with a sealed lid, through which saturated water vapor is introduced via a side tube, and the bottom of the chamber is cooled by placing it on an ice tray.

Evaluation guide:
(i) Target concept: Vapor condensation nucleation driven by localized conductive cooling at chamber base.
Minimum mechanism: Saturated vapor must be present; bottom surface temperature must fall below dew point; nucleation sites must be sparse enough to allow discrete floc growth (not continuous film); gravity must dominate over Brownian motion to enable bottom accumulation.
(ii)Storyline: Frame 1–2: Clear chamber on ice tray, side tube attached, no clouds. Frame 3–4: First floc-like cloud cluster appears near bottom, no prior haze. Frame 5–7: Additional floc clusters emerge sequentially at bottom, increasing in number/density; no upward migration or wall adhesion. Frame 8–10: Clusters remain confined to bottom region with soft, non-coalescing boundaries; chamber walls and lid stay dry and transparent; side tube and ice tray retain fixed spatial relationship throughout. Perspective: Fixed frontal view, centered on chamber, full chamber height visible, no occlusion.

Manual:
Experimental Procedure
1. Place transparent plastic chamber with sealed lid on ice tray.
2. Introduce saturated water vapor into chamber via side tube.
Observation of Experimental Phenomena
Floc-like small droplet clouds form spontaneously within clear chamber airspace; cloud clusters gradually accumulate at chamber bottom.
Summary of Experimental Principles
Cooling the chamber bottom condenses saturated water vapor into suspended micro-droplets; floc morphology arises from diffusion-limited nucleation near cold surface; gravitational settling concentrates clusters at bottom.

Prompt Grounding rubric:
level_1: The transparent chamber, its sealed lid, the side tube, or the ice tray is missing altogether; none of these four items appear together in a coherent setup.
level_2: At least one of the chamber, lid, side tube, or ice tray is present, but they are not arranged correctly together: for instance the chamber does not actually sit on the ice tray, the side tube does not connect to the chamber wall, or the vapor entry point is mislocated (e.g., coming in from above rather than through the side tube).
level_3: The transparent chamber with its sealed lid is fully visible, the side tube is attached to the chamber wall and points horizontally into the interior, and the ice tray sits directly under the chamber's base; all four items appear together, correctly arranged, from one fixed camera position.
level_4: Everything described at the 3-point level still holds, and in addition the side tube's connection to the chamber wall is visibly sealed (a gasket, port, or seam, not just resting against it), the ice tray supports the chamber's entire footprint with no gap or overhang at the base, the chamber itself never moves, and no hands, labels, or unrelated equipment enter the frame.
level_5: Everything described at the 4-point level still holds, and in addition the side tube's opening sits inside the chamber's interior rather than just touching the outer wall, the lid sits fully seated with no visible gap, the ice tray is in direct, flush contact with the chamber's base across its whole surface, and nothing about the chamber, lid, tube, or tray is ever cropped out of frame or distorted by the camera angle.

Scientific and Causal Correctness rubric:
level_1: No cloud-like clusters ever appear: instead the chamber stays a uniform fog, forms one solid condensation film, or shows no visible change at all; or the visible droplets are large beads, streaks, or a continuous sheet rather than small floc-like clumps; or whatever haze appears settles at the top, side, or middle rather than the bottom.
level_2: Something cloud-like appears, but it fails the core science: either it is visible from the very first frame instead of forming out of clear air (pre-existing mist, splashed water, or artificial smoke), or it looks like a continuous haze or beads rather than small discrete floc-like clumps, or it drifts upward, disperses through the middle, or settles somewhere other than the chamber's bottom.
level_3: Floc-like clusters of small droplets appear out of clear air inside the chamber, with no haze present beforehand, and these clusters gradually build up at the bottom of the chamber; no large droplets, rivulets, or frost form on the walls or lid, and the only state change visible is vapor turning into these suspended micro-droplet clusters, not liquid pooling or ice.
level_4: Everything described at the 3-point level still holds, and in addition the sequence is correct: the chamber interior starts perfectly clear, the floc-like clusters appear only after the chamber has been sitting on the ice tray for a moment, and the cloud density builds up gradually rather than in sudden bursts; nothing resembling dust specks, lens flare, or digital noise is mistaken for cloud structure.
level_5: Everything described at the 4-point level still holds, and in addition every cluster shows the characteristic floc look: soft, irregular, branching edges with fine, cotton-like granularity visible to the eye rather than smooth or bead-like surfaces; the clusters stay suspended rather than falling like rain or merging into a solid sheet; the buildup stays confined to roughly the bottom third of the chamber with a fairly distinct upper edge; and no condensation ever appears on the chamber walls, the lid, or inside the side tube.

Spatiotemporal Consistency rubric:
level_1: The chamber appears to jump from one position to another between shots; the ice tray vanishes or appears without being placed; the side tube disconnects and reconnects with no motion in between; the chamber visibly warps, bends, or rotates in a way a rigid plastic box cannot; the camera viewpoint switches abruptly mid-video; or the lighting on/around the chamber flickers or flips abruptly between frames (e.g., a sudden bright-to-dark strobe) with nothing shown to explain the change.
level_2: At least one clear break shows up: the chamber or ice tray shifts by more than half its width between key moments, the side tube detaches and reattaches with no in-between frames, the whole frame suddenly flips from bright to dark (or back) by more than half its brightness, or the lid appears to open or close with no visible mechanical motion.
level_3: The chamber stays in one place, the ice tray stays fully underneath it, and the side tube stays rigidly attached the whole time; the light illuminating the chamber stays constant in position and brightness, so shadows cast by the chamber, lid, and side tube keep the same direction and depth throughout; nothing pops in or out of view, and the chamber walls and lid never tear, stretch, or warp.
level_4: Everything described at the 3-point level still holds, and in addition any motion looks physically real: if the chamber is set onto the ice tray, that happens as one continuous motion rather than a jump-cut, and if vapor is entering via the side tube, it flows smoothly in one direction without stuttering or reversing; background elements never shift oddly relative to the chamber's edges from one frame to the next.
level_5: Everything described at the 4-point level still holds, and in addition the video plays at a consistent, natural speed with no duplicated or skipped frames; any blur present matches how fast each object is actually moving (the chamber isn't blurred while the ice tray next to it stays perfectly sharp, for instance); the lighting across the chamber's face doesn't drift or shift over time; and the focus stays consistent rather than racking between the chamber and ice tray.