Domain: Engineering — Geotechnical Engineering
Target concept: Comparison of Drainage Rates between Dry and Compacted Soils

Video generation prompt: Two identical transparent vertical containers are placed side by side: the left one is filled with loose dry soil, and the right one with compacted soil. Each container has a mesh structure at the bottom and is placed on a tray. Water is simultaneously poured into both containers in equal amounts.

Evaluation guide:
(i) Target concept: Differential permeability governed by soil density and pore connectivity.
Minimum mechanism: Water must move solely via gravity-driven flow through interconnected pores; soil must remain rigid and unsaturated during test; no capillary rise or surface runoff dominates; outflow must originate exclusively from mesh-bottom drainage.
(ii)Storyline: Frame opens on static side-by-side setup (containers, soil, mesh, tray) → water pouring action initiates synchronously into both containers → water infiltrates soil surfaces visibly → water emerges from mesh bottoms into trays → water level recedes faster in left container → outflow volume and rate visibly differ by video end; fixed frontal viewpoint, full-container framing, no occlusion of soil surface, mesh, or tray accumulation zone.

Manual:
Experimental Procedure
1. Place two identical transparent vertical containers side-by-side on a single tray.
2. Fill left container with loose dry soil; fill right container with compacted soil.
3. Ensure mesh structure is visible at bottom of both containers.
4. Simultaneously pour equal amounts of water into both containers.
Observation of Experimental Phenomena
Water drains faster from left (loose dry) container than from right (compacted) container; outflow is visible from mesh into tray under each; water level drops more rapidly in left container.
Summary of Experimental Principles
Loose dry soil has higher porosity and permeability than compacted soil, resulting in faster drainage under identical hydraulic head.

Prompt Grounding rubric:
level_1: One or more of the required physical elements is entirely missing: no two transparent vertical containers appear, or the containers are not placed side by side, or no mesh structure is visible at the bottom of either container, or no tray sits beneath the containers, or one or both containers hold no soil at all, or no water is poured into either container.
level_2: Both transparent containers, both mesh structures, the tray, and soil in both containers are all present and side by side, but the two soil types cannot be told apart by eye (e.g., both look equally loose or equally compacted); or water is poured into only one container; or the pouring into the two containers clearly starts at different times, with one pour well underway or finished before the other begins.
level_3: Two transparent vertical containers sit side by side on the same tray, each with a visible mesh structure at its base; the left container holds loose, dry soil and the right holds compacted soil; pouring water into both containers begins at the same visible moment with no noticeable gap between the two starts, using what looks like the same amount of water for each.
level_4: Everything required for a 3 is present, and in addition the two soil types look clearly different by eye: the left soil looks loose and clumpy with visible air pockets between grains, while the right soil looks dense, smooth-surfaced, and compacted with no visible voids; the pouring motion into each container matches in height, arc, and speed, and no water splashes out of either container during pouring.
level_5: Everything required for a 4 is present, and in addition nothing in the frame undermines the setup: both containers stay upright on the tray for the whole video, the mesh and soil surface of each container stay visible and unobstructed, the tray remains visible beneath both containers, and no container, soil, or pouring hand appears duplicated, mirrored, or cloned anywhere in the frame.

Scientific and Causal Correctness rubric:
level_1: No water ever exits through either container's mesh into the tray, so no drainage comparison is possible; or the compacted-soil (right) container visibly empties faster than the loose dry-soil (left) container, reversing the expected result; or the soil itself dissolves, floats away, or washes out through the mesh instead of staying in place.
level_2: Outflow appears at the bottom of at least one container, but the comparison fails to show any difference: outflow is visible from only one container with nothing coming from the other, or outflow appears from both containers at a rate that looks the same by eye for the entire video, or the water level inside both containers falls at visually the same pace throughout.
level_3: Water drips or streams out of the mesh at the bottom of both containers into the tray; the water level inside the left (loose dry soil) container falls faster than inside the right (compacted soil) container; water visibly collects in the tray beneath both containers; the soil itself stays in place with no visible erosion, cloudiness, or color change in the outflow.
level_4: Everything required for a 3 is present, and in addition the difference grows more evident over time: the left container's water level keeps dropping faster and by a larger total amount than the right's by the end of the video; the left container's outflow starts sooner and looks like a fuller stream or produces a visibly larger puddle in its tray; the right container never shows water pooling on top of its soil surface partway through the video.
level_5: Everything required for a 4 is present, and in addition the contrast stays clear and uninterrupted throughout: the soil in both containers stays solid and undisturbed; the outflow water in both trays looks clear, with no discoloration or bubbling; the left container's outflow stays steady and strong the whole time, while the right container's outflow stays visibly slower and may start and stop; by the final frame the tray beneath the left container clearly holds more water than the tray beneath the right container.

Spatiotemporal Consistency rubric:
level_1: One or both containers jump to a different position or size between frames with no visible movement causing it; the mesh at the bottom of a container, or the tray itself, is missing for a stretch of the video and then reappears later; soil shifts position on its own with no water touching it; water appears or disappears from the frame with no pouring or draining motion connecting the two states; the camera cuts or jumps to a different angle mid-scene; or the lighting flashes or flickers abruptly with no source causing it.
level_2: One container shakes or vibrates in place without any physical cause; the mesh at the bottom of a container blinks out of view for a single frame and back before settling; the water stream breaks into disconnected segments for a moment instead of flowing continuously; the tray's surface reflection changes brightness inconsistently with the rest of the scene; the soil surface shows grains shifting on their own in a way unrelated to water soaking in.
level_3: Both containers stay upright and in the same position relative to each other and to the tray for the entire video; the mesh stays visibly fixed at the bottom of each container; the tray stays fully visible and does not move; the poured water follows one continuous, connected path into each container; the direction of the shadows cast by the containers stays the same from the first frame to the last.
level_4: Everything required for a 3 is present, and in addition the containers show no barrel- or pincushion-style bulging or warping of their straight vertical edges; the water stream does not stretch or squeeze unnaturally as it falls; the soil's granular texture stays recognizable and consistent rather than shifting or shimmering; the soil surface in front stays correctly in front of, and the tray edge behind it stays correctly behind, throughout.
level_5: Everything required for a 4 is present, and in addition the whole scene reads as one coherent physical moment throughout: no blur hides the mesh or the point where water exits into the tray; no container, soil column, or water stream appears duplicated or ghosted; water in the left container never appears to pass in front of the right container's soil when it should be behind it; every edge of the containers, mesh, and tray stays crisp and in its expected place from start to finish.