Domain: Natural Science — Physics
Target concept: Comparison of heating water to boiling on a stove with and without a lid

Video generation prompt: On the stove, place two identical pots on adjacent burners, add equal amounts of water to each pot, and set the heat to the same level. Cover the pot on the left and leave the pot on the right uncovered, then ignite the burners simultaneously.

Evaluation guide:
(i) Target concept: Boiling point attainment rate depends on system openness due to latent heat retention.
Minimum mechanism: Water must remain liquid-phase throughout heating; lid must prevent vapor escape without sealing hermetically (i.e., allow slow pressure equilibration); stove must supply constant thermal power; ambient air must be cooler than boiling water to enable convective loss from uncovered pot.
(ii)Storyline: Frame 0–1: Static wide shot showing stove with two empty identical pots on adjacent burners. Frame 2–3: Water poured identically into both pots (surface level aligned). Frame 4: Lid placed fully on left pot; right pot remains open. Frame 5: Both burners ignited simultaneously (flames appear together). Frame 6–8: First steam/bubbling emerges exclusively from left pot. Frame 9–10: Steam/bubbling appears in right pot; left pot steam remains denser and more continuous. Throughout: Fixed frontal viewpoint; no occlusion; all objects maintain physical plausibility and spatial coherence.

Manual:
Experimental Procedure
Place two identical pots on adjacent stove burners. Add equal amounts of water to both pots. Cover left pot with a lid; leave right pot uncovered. Ignite both burners simultaneously.
Observation of Experimental Phenomena
Steam and vigorous bubbling appear first in the covered (left) pot, then later in the uncovered (right) pot. By end of observation, both pots show boiling, but left pot exhibits earlier onset and more intense activity.
Summary of Experimental Principles
Covering a pot reduces heat loss via evaporation and convection, allowing water temperature to rise faster to boiling point — demonstrating energy conservation and phase-change thermodynamics in closed vs. open systems.

Prompt Grounding rubric:
level_1: No stove is shown, or fewer than two pots appear, or no water is visible in either pot, or no lid appears anywhere in the shot, or neither burner is lit.
level_2: A stove and two pots are visible, but the setup breaks the described contrast: the two pots are not clearly identical in size/shape, or water is missing from one pot, or the lid is missing from the left pot, or a lid is also on the right pot, or the two burners are not lit at essentially the same moment, or the pots are not on burners next to each other.
level_3: A stove holds two visibly identical pots on neighboring burners, each containing a similar amount of water; a lid sits on the left pot only, the right pot has no lid; both burners are ignited at essentially the same moment; the two pots stay next to each other in frame for the whole video.
level_4: Everything in the 3-point level holds, and additionally: the lid fully covers the left pot's opening with no visible gap along its rim; the water lines in the two pots look about the same height; the two flames are similar in size and color; no extra props (spoons, timers, thermometers, etc.) appear in the shot.
level_5: Everything in the 4-point level holds, and additionally: the lid never lifts, tilts, or slides off the left pot at any point in the video; water stays visibly present in both pots the entire time (it never abruptly disappears); both flames stay lit without ever going out or reigniting; the camera keeps the same framing on both pots from start to finish.

Scientific and Causal Correctness rubric:
level_1: Neither pot shows any steam, rising bubbles, or surface agitation at any point; the water in both pots looks like it stays cold and undisturbed throughout.
level_2: Steam or vigorous bubbling shows up in only one of the two pots while the other never boils at all, or both pots begin steaming/bubbling at essentially the same moment with no noticeable difference between them, or the right (uncovered) pot begins boiling before the left (covered) pot.
level_3: The left, covered pot shows visible steam or vigorous bubbling before the right, uncovered pot does; by the end of the video both pots are showing some boiling activity; the right pot is never seen boiling ahead of the left pot.
level_4: Everything in the 3-point level holds, and additionally: once both pots are boiling, the left pot's steam looks noticeably thicker or more continuous than the right pot's, and its bubbling looks earlier and more sustained, at every point where the two can be compared.
level_5: Everything in the 4-point level holds, and additionally: throughout the whole time both pots are actively boiling, the left, covered pot keeps looking more vigorous overall (thicker steam and/or livelier bubbling) than the right, uncovered pot; the right pot never catches up to or surpasses the left pot's boiling intensity at any comparable moment.

Spatiotemporal Consistency rubric:
level_1: A pot or the lid abruptly disappears from the shot and then pops back into view in a different spot; a flame jumps from one burner to the other without any spreading motion; the lid appears floating above a pot's rim with a visible gap instead of resting on it; the water surface's height changes in a sudden jump rather than gradually; the whole scene swings from bright to dark lighting (or the reverse) within a single moment.
level_2: One clear major break in continuity occurs: for example, the lid appears already resting on the pot with no moment of it being placed, or a burner's flame is shown fully lit with no ignition moment, or the water level in a pot drops suddenly without visible steam loss explaining it, or the pots shift position on the stovetop without a smooth, continuous movement.
level_3: The two pots stay fixed on their own burners for the whole video; the lid stays touching the rim of the left pot the entire time it's shown; each flame stays under its own pot without wandering; the water surface only moves through visible bubbling or steam release rather than sudden unexplained jumps; steam rising from either pot moves upward in a continuous stream rather than blinking in and out of existence or jumping location between moments.
level_4: Everything in the 3-point level holds, and additionally: the lid does not shake or jitter independently of the pot it sits on; the flames flicker in a way that looks similar in scale for both burners; the bubbling and steam motion looks continuous and gravity-consistent (bubbles and steam rise upward rather than sinking or moving sideways unnaturally); the lid's edge never appears to pass through or overlap the pot wall in an impossible way.
level_5: Everything in the 4-point level holds, and additionally: the video shows no frozen or repeated frames, no sudden jump in overall scene brightness, and no jump in camera framing at any point; the relative sizes and positions of the two pots stay consistent with each other the whole time, matching a single fixed camera viewpoint; the lid's rim stays one continuous, unbroken ring throughout: it is never seen breaking apart into disconnected pieces or visibly tearing.