Domain: Natural Science — Marine Science
Target concept: Growth of Attached Organisms on Marine Ecological Reef Structures

Video generation prompt: Porous stone was placed in a clear seawater tank to simulate a coral reef, and seawater containing trace amounts of algae was continuously introduced to record the process of algal attachment.

Evaluation guide:
(i) Target concept: Flow-dependent, substrate-selective microbial colonization on complex topographies.
Minimum mechanism: Algal cells must be suspended in moving water, make physical contact with porous surface features, and adhere selectively to micro-topographic irregularities, not smooth surfaces or inert materials, under laminar flow conditions.
(ii)Storyline: [Frame 0–2] Porous stone placed statically in empty clear tank; [Frame 3–4] Liquid stream enters tank from top edge, making first visible contact with upper stone surface; [Frame 5–8] Texture change emerges *only* at contact zone, expands gradually across adjacent porous regions, remains absent on tank walls/glass and non-porous stone faces; [Frame 9–10] Change persists and intensifies locally without spreading to liquid column or background; all under fixed frontal view with consistent lighting and no occlusion.

Manual:
Experimental Procedure
1. Place a porous stone inside a clear, transparent seawater tank.
2. Introduce a continuous, gentle stream of clear seawater containing trace suspended algae into the tank from above.
Observation of Experimental Phenomena
A gradual, localized textural change (increased granularity and faint greenish tint) appears first at the stone region directly contacted by the algal stream, spreading slowly across porous surfaces while remaining absent on tank walls and non-porous areas.
Summary of Experimental Principles
Algal attachment initiates at sites of direct fluid contact and preferentially colonizes micro-roughness of porous substrates—demonstrating substrate selectivity and flow-mediated biofilm nucleation in marine benthic ecosystems.

Prompt Grounding rubric:
level_1: No porous stone is visible; no clear seawater tank is present; no stream of liquid entering the tank is shown; none of these three elements (stone, tank, inflow) appear in the video at all.
level_2: Only one of the three core elements appears (a stone, or a tank, or a liquid stream) and it has the wrong appearance (e.g., a smooth non-porous rock instead of a porous stone, an opaque container instead of a clear tank, or a colored liquid unlike clear seawater); no placement action of the stone into the tank is shown.
level_3: A visibly pitted/porous stone, a clear rectangular tank, and a continuous stream of liquid entering the tank are all present and correctly typed; the stone is shown placed inside the tank before the liquid stream begins, in that order.
level_4: In addition to the 3-point requirements, the liquid stream is shown entering from a visible inlet (a pipe or tube end at the tank's edge) rather than appearing to originate from nowhere, and the stone stays in one fixed position, fully underwater, for the entire video.
level_5: In addition to the 4-point requirements, the stone sits in the lower third of the frame, the liquid stream enters only at the top edge of the tank (not from the side or bottom), and no other object (a hand, a tool, a label) ever enters the frame.

Scientific and Causal Correctness rubric:
level_1: No visible sign of biological attachment: the stone's surface looks the same at the end of the video as at the start, and there's no visible link between the incoming liquid and any surface change.
level_2: The stone's surface changes color or texture, but the timing is wrong: the change starts before the liquid ever touches the stone, or it continues even after the liquid stops flowing; or the incoming liquid looks green/cloudy the whole time while the stone itself never visibly changes; or the change appears on the tank wall rather than the stone.
level_3: After the liquid stream visibly touches the stone, a localized change appears on the stone's surface (a grainier texture, faint speckling, or a light greenish tint) starting right at the point of contact; the tank walls and the liquid itself show no such change.
level_4: In addition to the 3-point requirements, the surface change visibly spreads outward from the initial contact point across the stone over the course of the video, and the liquid stays clear/translucent throughout with no settling sediment visible.
level_5: In addition to the 4-point requirements, the surface change only appears on the stone's rough, porous-looking regions and not on its smooth edges or flat faces, and there is no non-biological artifact (bubbles, condensation, glare, or reflections) that could be mistaken for attachment.

Spatiotemporal Consistency rubric:
level_1: Severe spatiotemporal rupture: the stone appears inside the tank without ever being placed there; the room lighting swings from full brightness to near-total shadow within the same shot; part of the tank's edge disappears and reappears; or the stone's position jumps between frames with no continuous motion.
level_2: One major continuity flaw: the liquid stream is shown flowing before its inlet is ever visible; the stone rotates by more than about 15 degrees with no visible cause; the direction of the stone's shadow changes without any visible change in the light; or the tank's reflection shows a background that doesn't match between shots.
level_3: No teleportation, no vanishing tank edges, no unexplained reversal of shadow direction, and no jump cuts; the stone stays fixed in position and orientation, the liquid stream keeps a consistent entry angle and flow direction, and the tank walls and base stay continuously visible and geometrically stable.
level_4: In addition to the 3-point requirements, the liquid's surface stays level with no splashing, bubbling, or ripples that would be out of place for a gentle, steady inflow, and the stone casts a steady, soft shadow that stays aligned with the light throughout.
level_5: In addition to the 4-point requirements, the liquid surface's motion is smooth and continuous with no freezing or flickering between frames, and the stone and the tank background show no relative shift that would suggest camera movement or a composited shot.