Domain: Healthcare — Nutrition & Dietetics
Target concept: Salt causes water loss from tomato cells through osmosis, resulting in exudation.

Video generation prompt: Take two identical plates, place one slice of fresh tomato on each. Sprinkle a small amount of salt on one tomato, and leave the other unsalted. Allow them to stand at room temperature for 30 minutes, then observe both tomato slices closely.

Evaluation guide:
(i) Target concept: Osmotic water loss from plant cells induced by external solute concentration gradient.
Minimum mechanism: Intact tomato epidermis and parenchyma cells must be present; salt must remain extracellular and undissolved initially; water must exit cells into intercellular spaces and accumulate on surface as free liquid, not evaporation, condensation, or mechanical damage.
(ii)Storyline: [Frame 0–2] Two identical plates enter static view, each with one fresh tomato slice (uniform red, moist but dry surface); [Frame 3–4] Hand deposits white granular salt exclusively onto left tomato slice; [Frame 5–10] Side-by-side fixed-view observation: salted tomato develops transparent, coalescing liquid beads/pools on surface; unsalted tomato remains completely dry; no occlusion, no lighting shift, no motion beyond natural settling; causal sequence salt → exudation (not reverse or simultaneous).

Manual:
Experimental Procedure
1. Place two identical plates side-by-side.
2. Put one fresh tomato slice on each plate.
3. Sprinkle salt onto only one tomato slice.
4. Observe both tomatoes simultaneously for visible water exudation.
Observation of Experimental Phenomena
Water droplets or pooled liquid appear only on the salted tomato; the unsalted tomato remains dry.
Summary of Experimental Principles
Salt creates a hypertonic environment outside tomato cells, causing water to move out via osmosis, resulting in visible exudation.

Prompt Grounding rubric:
level_1: The core setup is missing: no two plates are shown, no tomato slices appear, salt is never applied to anything, and there's no shot showing both tomato slices together for comparison.
level_2: Pieces of the setup are wrong: the two plates differ noticeably in size or are never shown together at the same time; only one tomato slice appears anywhere in the frame; salt is visible but never lands on a tomato slice; the unsalted slice is missing entirely; or the two plates are not shown next to each other in a single steady shot.
level_3: Two matching plates are shown, each holding one fresh tomato slice; salt is sprinkled on exactly one of the two slices; the unsalted slice is clearly visible and distinguishable from the salted one; the two plates stay next to each other in the frame for the whole clip; the camera holds one steady view showing both tomatoes at once.
level_4: Everything in the 3-point level holds, and in addition: the two tomato slices look the same size, shape, and surface texture at the very start; the salt sits as visible individual grains on one slice only, not dissolved into liquid or smeared across the surface; nothing else (a spoon, a hand mid-motion, or similar) blocks the view of either tomato while they're being observed.
level_5: Everything in the 4-point level holds, and in addition: no hand or utensil remains in the shot during the observation period; both tomato slices stay fully visible the whole time, with no cropping, zooming, or repositioning; the salt is applied and visible before any liquid appears on either slice; aside from at most one time-compression transition standing in for the prescribed 30-minute standing period, there is no other cut, camera change, or repositioning between salting the tomato and watching what happens afterward.

Scientific and Causal Correctness rubric:
level_1: No liquid shows up on either tomato slice; both look dry and unchanged from start to finish; there's no visible difference in moisture between the two slices; nothing ties the appearance of any liquid to the salt.
level_2: Liquid shows up on both tomato slices equally; or liquid shows up only on the unsalted slice; or liquid appears before the salt is even sprinkled; or the liquid shown looks like something other than exuded tomato juice (e.g., it looks like condensation, a spill, or droplets added from outside).
level_3: Liquid clearly beads up or pools only on the salted tomato slice; the unsalted slice stays dry with no visible surface moisture; the liquid on the salted slice looks like pooled or beaded fluid rather than mist, fog, or a light sheen; the difference in moisture between the two slices is easy to see by eye.
level_4: Everything in the 3-point level holds, and in addition: the liquid clearly comes from the tomato flesh itself rather than an outside source; it looks clear and watery, not colored, thick, or cloudy; the salted tomato doesn't visibly dry out, crack, or shrivel during the short observation window (only the appearance of liquid is required).
level_5: Everything in the 4-point level holds, and in addition: there is no liquid on the salted tomato at the very start of the clip, and it only appears after the salt has been sprinkled; the unsalted tomato never shows any liquid at any point; the liquid on the salted tomato visibly grows in amount or spreads further across the surface as the clip goes on, matching a steadily building osmotic response.

Spatiotemporal Consistency rubric:
level_1: A major break in continuity: one of the plates suddenly appears in a different spot with no motion shown in between; a tomato slice's position or orientation jumps without any transition; the lighting or shadows suddenly change in a way unrelated to the room's actual lighting; a tomato slice appears to split apart or come apart in a way that couldn't happen on its own.
level_2: A noticeable but less severe break: one of the tomato slices vanishes from view and then comes back; the edge of a plate visibly warps or stretches; the salt grains disappear and then reappear; the lighting swings suddenly brighter or darker partway through the clip; the motion looks jerky or a moment seems to repeat.
level_3: Neither plate nor tomato jumps position, disappears, or reappears; the two plates and tomato slices stay in the same relative spots to each other throughout; the lighting on the scene looks even and doesn't swing in brightness or angle; nothing visibly warps, tears, or morphs; any motion shown (such as a hand sprinkling salt) looks like something a person could actually do.
level_4: Everything in the 3-point level holds, and in addition: the camera itself doesn't pan, tilt, or zoom; the two plates don't shift relative to each other as if the camera were moving unevenly; there's no flickering or strobing between frames; the plate rim stays wrapped around the base of its tomato slice the same way throughout, with no odd gaps or overlaps appearing.
level_5: Everything in the 4-point level holds, and in addition: aside from at most one time-compression cut or dissolve standing in for the prescribed 30-minute wait, the clip plays as one continuous take with no other cuts, dissolves, or speed changes; if a hand appears to sprinkle the salt, its motion looks smooth and unbroken and finishes before the observation period begins; there's no shakiness or flicker along the edges of the plates or tomato slices that would make them hard to look at clearly.