Domain: Natural Science — Ecology & Evolutionary Biology
Target concept: Turbid water flowing through the soil tray is filtered by wetland plants.

Video generation prompt: Two shallow soil trays were placed side by side, one planted with wetland vegetation and the other bare; the same turbid water was poured into both, flowing into the transparent containers below.

Evaluation guide:
(i) Target concept: Wetland vegetation enhances soil filtration efficiency for suspended solids in surface runoff.
Minimum mechanism: Rooted hydrophytes create biologically active rhizosphere that traps particulates and promotes microbial/flocculation processes; bare soil lacks biological binding and exhibits higher erodibility and lower retention capacity.
(ii)Storyline: Frame opens on static wide shot showing two identical shallow trays side-by-side on flat surface, with distinct vegetation in left tray and exposed soil in right tray; transparent containers already positioned directly beneath each tray; turbid water (brownish-gray, opaque suspension) is poured vertically into each tray center in synchronized motion; water percolates visibly through soil layers; effluent drips into containers; clarity divergence emerges progressively as containers fill: left container shows increasing transparency revealing bottom surface, right container retains uniform opacity; viewpoint remains fixed, no cuts, no occlusions, no repositioning.

Manual:
Experimental Procedure
- Place two identical shallow soil trays side-by-side.
- Plant wetland vegetation in left tray; leave right tray bare.
- Simultaneously pour identical volumes of turbid water into both trays.
- Observe water flowing through soil into transparent containers below.
Observation of Experimental Phenomena
- Water collected in container under vegetated tray is visibly clearer.
- Water collected in container under bare tray remains turbid.
Summary of Experimental Principles
- Turbid water flowing through the soil tray is filtered by wetland plants.

Prompt Grounding rubric:
level_1: The scene shows no soil trays, no turbid water being poured, and no transparent containers beneath the trays; or only a single tray is shown alone with nothing beside it.
level_2: One soil tray is visible and turbid water is poured into it, but the second tray is missing, or the two trays are positioned one behind the other instead of beside each other, or no transparent container sits under either tray.
level_3: Two soil trays sit right next to each other in the same shot, one clearly holding rooted wetland vegetation and the other showing exposed bare soil; a transparent container sits directly beneath each tray; brownish-gray turbid water is poured into both trays.
level_4: All elements of score 3 are present, and the water is poured into both trays at the same time with a matching pouring motion; the vegetated tray's plants (stems and leaves) are clearly distinguishable from the bare tray's exposed soil at a glance; both containers stay in place and fully visible for the whole clip.
level_5: All elements of score 4 are present, and the two trays keep the same spacing next to each other for the entire clip with no repositioning and neither tray passing in front of the other; the two pour streams look symmetric: matching height and angle, entering each tray at the same moment; neither tray nor container leaves the frame at any point from the first pour to the final still shot.

Scientific and Causal Correctness rubric:
level_1: The two containers end up equally murky, or the container beneath the bare-soil tray ends up clearer than the container beneath the vegetated tray, or no turbid water ever reaches either container.
level_2: Turbid water reaches both containers, but there is no visible clarity difference between them by the end, or the bare-soil tray's container turns out clearer while the vegetated tray's stays murkier, or the vegetation shows up as loose floating debris rather than plants rooted in the soil.
level_3: By the end of the pour, the container beneath the vegetated tray is visibly clearer than the container beneath the bare-soil tray, consistent with rooted wetland plants improving filtration; the water does not spontaneously darken again after the flow stops.
level_4: All elements of score 3 are present, and the clarity difference only becomes visible once the water has actually passed through each tray's soil: the water poured into the two trays looks equally murky before it enters the soil; the bare-soil tray's container stays turbid throughout with no unexplained clearing; the vegetation stays rooted in its tray the whole time rather than floating loose.
level_5: All elements of score 4 are present, and the contrast is unmistakable: the vegetated tray's container becomes clear enough that its base or far wall is visible through the water, while the bare-soil tray's container stays uniformly cloudy with no view through it; no water or sediment crosses between the two trays' setups, such as a shared spill path or overflow linking them.

Spatiotemporal Consistency rubric:
level_1: A tray or a container vanishes and reappears at some point in the clip; the water stream jumps straight from the pouring source into an already-full container with no visible travel between the two; the vegetation's position changes with no visible movement causing it; the overall scene brightness jumps abruptly partway through, as if a light had been switched.
level_2: A tray, container, or the vegetation flickers off and back on briefly; the poured water stream breaks apart or skips in mid-air instead of falling continuously; the vegetation whips back and forth violently and then suddenly freezes; the camera view noticeably shifts, tilts, or zooms at some point instead of holding still.
level_3: Both trays, both containers, and the vegetation keep the same size, position, and orientation relative to one another throughout; the poured water falls in an unbroken stream with no visible gaps or jumps; the vegetation stays rooted and does not slide or fall over; no tray, container, or plant disappears and reappears at any point.
level_4: All elements of score 3 are present, and neither tray's edges appear to slide past background objects at a speed that looks mismatched with a still camera; instead of appearing instantly full, the water level inside each container rises gradually and visibly as the pour continues; there is no repeated or stuttering replay of the same pouring motion.
level_5: All elements of score 4 are present, and the camera holds one fixed framing with no pan, tilt, or zoom for the entire clip; the soil surface of both trays visibly darkens and wets as water spreads across it, without dry patches suddenly appearing mid-pour; the water level in both containers climbs at a rate that matches how much has been poured rather than jumping in sudden steps; no part of the scene shows smeared, doubled, or trailing after-images of moving objects.