Domain: Healthcare — Nutrition & Dietetics
Target concept: Plastic wrap reduces water evaporation and oxidation, preventing cucumber dehydration and spoilage.

Video generation prompt: Take one fresh cucumber, cut it into two halves, wrap one half with cling film, and leave the other half unwrapped. Place both halves in a refrigerator at 4°C for 24 hours, then remove and compare.

Evaluation guide:
(i) Target concept: Barrier-mediated inhibition of moisture loss and oxidative degradation in plant tissue under refrigerated storage.
Minimum mechanism: Intact epidermis + cut surface exposure → water vapor diffusion + O₂ interaction → cellular dehydration and enzymatic browning; impermeable polymer film physically blocks vapor/O₂ exchange at interface.
(ii)Storyline: [Phase 1: Initial State] Fresh cucumber shown whole → cut cleanly into two symmetrical halves (exposing identical internal tissue). [Phase 2: Intervention] Cling film unrolled and fully covers cut+peel surface of one half; other half remains bare, cut surface fully exposed. [Phase 3: Storage Context] Both halves placed adjacently inside refrigerator interior (cold, humid, stable environment). [Phase 4: Outcome] After elapsed time, side-by-side comparison reveals differential surface state: unwrapped half exhibits macroscopically visible loss of turgor (wrinkling) and gloss (dullness); wrapped half preserves original surface integrity. Perspective must maintain fixed frontal view with consistent framing to enable direct visual contrast; all critical surfaces (cut faces, film coverage, adjacent positioning) must remain continuously visible and unoccluded.

Manual:
Experimental Procedure
1. Cut one fresh cucumber lengthwise into two equal halves.
2. Wrap one half tightly with clear cling film; leave the other half completely unwrapped.
3. Place both halves side-by-side on a refrigerator shelf at 4°C.
4. After 24 hours, remove and compare their appearances.
Observation of Experimental Phenomena
The unwrapped half shows visible surface dullness, slight wrinkling, and loss of tautness at the cut surface; the wrapped half retains glossy, smooth, and moist appearance with no dehydration signs.
Summary of Experimental Principles
Plastic wrap reduces water evaporation and oxidation, preventing cucumber dehydration and spoilage.

Prompt Grounding rubric:
level_1: No cucumber ever appears in the video; or the cucumber is never cut into two visible halves; or no cling film is ever shown; or the two cucumber halves are never shown near each other in the same shot; or no refrigerator or clearly cold storage space is ever shown or implied; or the video never reaches a moment where the two halves appear together for comparison.
level_2: The cucumber is cut into two pieces of clearly different size or shape rather than comparable halves; cling film appears but is never actually wrapped onto a half, or is wrapped onto both halves, or onto neither; the two halves are always shown apart in separate shots and never appear near each other in the same frame; the refrigerator interior itself is never shown - only implied by a scene cut with no cold-storage cue such as shelving, chilled mist, or frost - or the final comparison happens before either half is ever placed in the fridge.
level_3: The cucumber is cut into two similarly sized halves; one half is fully covered in transparent cling film while the other half is left completely bare with no covering of any kind; both halves rest near each other on the same shelf inside a refrigerator interior that is visibly cold (shelves, chilled-air cues, or frost are visible); a clock or on-screen time label is not required, but the refrigerated setting itself is clearly and unambiguously shown; the final shot places both halves together in the same frame so they can be compared directly.
level_4: Everything described at the 3-point level holds, and in addition the cling film covers only the intended half with no stray film touching the bare half and no gap or double layer in its coverage; the bare half's cut surface stays fully visible and is never blocked by a hand, utensil, or the edge of the film; both halves stay in the same position relative to each other on the shelf from the moment they are placed until the final comparison, without being moved or swapped; the refrigerator interior remains the visible setting throughout, without cutting away to an unrelated location and back.
level_5: Everything described at the 4-point level holds, and in addition both cut surfaces face the same direction and are shown at a matching angle so they can be fairly compared; the cling film lies smooth and taut over its half with no wrinkles or large air pockets that could hide the true condition of the surface beneath it; the bare half has nothing else resting on or draped over it that could be mistaken for a covering; the camera keeps both halves at a consistent distance and angle across the placement and comparison shots, with no zoom or angle change that makes them appear closer or farther apart than they really are; neither half moves into or out of frame during the comparison.

Scientific and Causal Correctness rubric:
level_1: After refrigeration, the two halves show no visible difference in surface condition at all; or the wrapped half looks drier and more shriveled than the unwrapped half; or the unwrapped half looks glossy and moist while the wrapped half looks matte and dull; or the unwrapped half's color changes to something implausible for a cut cucumber (e.g., turning blue-grey) while the wrapped half stays bright green; or neither half's cut surface is ever actually visible.
level_2: Both halves look identical in surface texture and moisture at the end, showing no protective effect of the film at all; or the wrapped half ends up just as wrinkled and dull as the unwrapped half (the film provided no visible benefit); or the unwrapped half shows mold or visible rot, an outcome implausible for only 24 hours of refrigeration; or the cut surface under the film turns yellow or brown while the unwrapped cut surface does not, suggesting the film accelerated spoilage rather than preventing it.
level_3: The unwrapped half shows visible surface change compared to the wrapped half: its cut surface looks duller, slightly wrinkled, or less plump; the wrapped half keeps a smoother, glistening, plump-looking cut surface; both halves remain the same green color with no browning or yellowing on either one; neither half shows spoilage signs such as sliminess, dark spotting, or mold; both cut surfaces remain firm rather than soft or collapsed.
level_4: Everything described at the 3-point level holds, and in addition the visible difference is limited to the cut surface and nearby peel rather than spreading across the whole cucumber body; the wrapped half shows no sign of drying out anywhere, including its ends; the unwrapped half shows no unnatural pooling of liquid or unexplained sheen; both halves keep the same green color with no hue shift suggesting spoilage; the unwrapped half never looks firmer or glossier than the wrapped half.
level_5: Everything described at the 4-point level holds, and in addition the contrast is unmistakable: the unwrapped half shows visible micro-wrinkling and dulling concentrated right at the cut edge and adjoining peel, while the wrapped half keeps a continuous moist sheen across its entire covered surface including the cut face; no glare or reflection off the film is being used to fake a glossy look, and no unusual shadow is being used to make the unwrapped half's wrinkling look worse than it is; the lighting on both halves is even enough that the comparison is judged on the cucumber's actual surface state, not on lighting tricks.

Spatiotemporal Consistency rubric:
level_1: One or both cucumber halves vanish from a shot and reappear later with no cutting, wrapping, or carrying motion ever shown connecting the two moments; the cling film is shown already wrapped around a half with no unwrapping-to-wrapped transition ever shown; the refrigerator's interior changes to a completely different shelf, color, or layout between the placement shot and the final comparison shot; the wrapped and unwrapped halves swap positions between shots with no hand or motion shown moving either one; the lighting abruptly shifts (e.g., warm to cool, or bright to dim) between the placement and comparison shots with no light source change to explain it; or a cut surface flips to face the opposite direction between shots with no rotation motion shown.
level_2: The cutting motion is skipped entirely - the cucumber is simply shown already split into two halves; the cling film is shown already conforming to a half with no unrolling or draping motion visible; the two halves are shown apart in one shot and adjacent in the very next shot with no visible movement bringing them together; the video cuts from the refrigerator interior to an unrelated background (e.g., a countertop) between the wrapping and comparison steps.
level_3: The cutting, wrapping, and placement steps are each shown as continuous, visible motions - the blade visibly separates the cucumber into two halves, the cling film is unrolled and draped over one half so it visibly conforms to the surface, and both halves are carried or slid into place next to each other on the refrigerator shelf without any instant jump; the final comparison keeps both halves in the same shot without an unexplained scene change; even so, one small hitch is visible somewhere in this sequence, such as a brief flicker in the refrigerator's interior lighting or a short stutter partway through the film-wrapping motion, though neither half is ever missing, duplicated, or out of place.
level_4: Everything described at the 3-point level holds, and in addition there is no flicker, stutter, or momentary hitch left anywhere in the sequence - the cling film settles over its half smoothly without floating or jumping, no hand or utensil appears to pass through the cucumber or the film, a refrigerator door shown opening or closing swings through in one continuous motion, and the camera holds one fixed framing throughout so the two halves' positions relative to each other are never disrupted by a pan, tilt, or zoom.
level_5: Everything described at the 4-point level holds, and in addition the entire sequence from cutting through the final comparison plays out as one uninterrupted flow with no jump cuts between steps; the cling film conforms to the half at a natural, gradual pace rather than snapping instantly into place; the refrigerator shelf, any visible jars or racks, and the frost or condensation pattern on the interior walls stay identical in position and appearance across every shot from placement to final comparison; neither cucumber half, the cling film, nor the shelf ever flickers, ghosts, or warps at its edges.