Domain: Natural Science — Chemistry
Target concept: Hydrogen peroxide decomposition catalyzed by yeast produces rapid oxygen bubbles.

Video generation prompt: Two transparent glass containers are placed side by side, each containing an equal amount of hydrogen peroxide; moist bread yeast is added only to the left container, while the right one remains unchanged, with continuous real-time recording throughout the process.

Evaluation guide:
(i) Target concept: Catalytic decomposition of hydrogen peroxide by biological enzyme (catalase in yeast) produces gaseous oxygen as a visible effervescence phenomenon.
Minimum mechanism: Yeast must be biologically active (moist, not dried/dead), hydrogen peroxide must be aqueous and unstabilized, and physical contact between yeast and solution must occur to initiate enzymatic reaction; no external energy input (heat, light, electricity) required.
(ii)Storyline: [Phase 1: Baseline] Two filled containers shown side-by-side, both quiescent, no bubbles. [Phase 2: Intervention] Yeast applied exclusively to left container: visible contact with liquid surface/subsurface. [Phase 3: Causal Onset] Within ≤1 second of contact, first oxygen bubbles emerge at interface and rise continuously. [Phase 4: Contrast Manifestation] Bubbling intensifies in left container while right remains completely still; difference is visually unambiguous and sustained. [Phase 5: Continuity] All events unfold from fixed frontal viewpoint; no occlusion; no camera motion; no object entry/exit; bubble motion and liquid behavior obey macroscopic fluid/gas physics. Visibility constraints: yeast texture, bubble size/density, and liquid clarity must be sufficient for human observers to distinguish left/right states without annotation or zoom.

Manual:
Experimental Procedure
1. Place two identical transparent glass containers side-by-side on a flat surface.
2. Pour equal amounts of colorless hydrogen peroxide into both containers.
3. Add moist bread yeast only to the left container.
4. Record continuously from start to finish with fixed viewpoint.
Observation of Experimental Phenomena
Rapid, continuous stream of small-to-medium oxygen bubbles rises vertically in the left container only; no bubbles form in the right container; liquid remains colorless and clear in both; yeast remains visible as tan-brown granular mass in left container.
Summary of Experimental Principles
Yeast contains catalase enzyme that decomposes hydrogen peroxide (H₂O₂) into water and oxygen gas; this catalytic reaction occurs rapidly only where yeast contacts H₂O₂, producing visible O₂ bubbles.

Prompt Grounding rubric:
level_1: No two transparent glass containers visible; no hydrogen peroxide liquid present in either container; no moist bread yeast visible anywhere; no side-by-side spatial arrangement; no continuous recording evident (e.g., cut, jump, or static image only).
level_2: Two transparent glass containers are present and side-by-side, but at least one container lacks visible liquid, or yeast is absent from both containers, or yeast appears in the right container, or containers differ in material (e.g., one is plastic or opaque), or spatial arrangement is not fixed (e.g., camera pans or repositions mid-video).
level_3: Two transparent glass containers placed side-by-side, each containing a visible liquid consistent with hydrogen peroxide (colorless, still, surface-refractive); moist bread yeast is visibly present only in the left container (as granular/tan-brown clumps or slurry on liquid surface or submerged); right container contains no yeast; camera viewpoint remains fixed throughout; recording appears continuous (no cuts, jumps, or freezes).
level_4: All conditions for score 3 are satisfied, AND: yeast is applied only after both containers are already filled and stationary (i.e., no simultaneous pouring-and-adding); liquid volume in both containers appears subjectively equal (no obvious disparity in meniscus height or fill level); yeast is applied exclusively to left container with no contact or transfer to right container (no splatter, drip, or airborne particles landing in right container).
level_5: All conditions for score 4 are satisfied, AND: yeast is added as a distinct action visibly occurring only once, only to left container, with no residual yeast residue on tools or fingers entering frame; both containers remain fully within frame for entire duration; no occlusion of either container at any moment; no insertion or removal of objects during recording; no change in container position, orientation, or relative spacing.

Scientific and Causal Correctness rubric:
level_1: No oxygen bubble formation observed in either container; no visible difference between containers; liquid remains motionless and identical in both; no state change occurs; no causal link between yeast addition and bubbling is implied.
level_2: Bubbling occurs in only one container but not the left one; or bubbling occurs in both containers; or bubbling begins before yeast is added; or bubbles appear as large, slow, isolated globules inconsistent with rapid gas evolution; or liquid changes color in either container.
level_3: Rapid, continuous, fine-to-medium-sized oxygen bubbles appear exclusively in the left container starting after yeast addition; bubbles rise vertically through liquid and burst at surface; right container shows no bubbling: liquid remains still and undisturbed; no color change, phase separation, or precipitation in either container; bubbling persists for observable duration (≥2 seconds of visible activity).
level_4: All conditions for score 3 are satisfied, AND: bubble density in left container increases visibly over time (i.e., more bubbles per unit area in later frames vs. early frames after addition); bubble size distribution remains consistent (no sudden shift to foam, froth, or large coalesced bubbles); no bubble formation initiates in right container at any point; no dissolution, fading, or disappearance of yeast mass in left container during bubbling.
level_5: All conditions for score 4 are satisfied, AND: bubble emergence is temporally locked to yeast contact (first bubbles appear only after yeast makes physical contact with liquid surface or subsurface); no delay >1 second between visible contact and first bubble emergence; no bubble activity ceases prematurely (bubbling remains continuous and vigorous until end of video); no anomalous phenomena (e.g., smoke, steam, effervescence unrelated to gas release, or liquid overflow).

Spatiotemporal Consistency rubric:
level_1: Containers teleport (suddenly change position/orientation), vanish/reappear, or undergo impossible deformation; liquid surface exhibits instantaneous discontinuous displacement (e.g., jump-cut level change); light/shadow flickers erratically or contradicts fixed light source; camera motion violates fixed viewpoint (e.g., zoom, pan, tilt, or rotation).
level_2: Minor spatial discontinuity: one container shifts slightly (<10% of width) without motion blur; liquid surface ripples without cause (e.g., no vibration, air current, or impact); shadow shape mismatches object geometry; frame rate instability causes strobing or ghosting in moving bubbles.
level_3: All objects maintain stable position and orientation; liquid surfaces show natural, physically plausible motion (e.g., gentle ripple propagation, bubble-induced surface distortion); shadows remain consistent in direction, softness, and attachment to objects; no object clipping, warping, or interpenetration; motion of rising bubbles follows smooth vertical trajectories with natural acceleration/deceleration.
level_4: All conditions for score 3 are satisfied, AND: bubble motion is consistently upward with no lateral drift or sinking; no temporal aliasing (e.g., bubbles freeze mid-rise then jump); no abrupt lighting shift (e.g., brightness/color temperature change) across frames; no structural artifact (e.g., container edge tearing, liquid transparency inconsistency, or reflection discontinuity).
level_5: All conditions for score 4 are satisfied, AND: inter-frame motion of bubbles shows continuous, unbroken trajectories (no skipped positions or teleportation between frames); container edges remain sharp and geometrically consistent; liquid transparency and reflectivity are uniform across both containers and stable over time; no inter-object occlusion inconsistency (e.g., bubble appearing behind container wall then in front without crossing plane).