Domain: Healthcare — Medicine
Target concept: Identification Test of the Drug (Fehling's Reaction)

Video generation prompt: A transparent test tube containing 1 mL of glucose injection was placed on the desk. Then, 2 mL of alkaline copper tartrate reagent was added, and the mixture was heated in a water bath for 3 minutes. The reaction phenomenon was observed.

Evaluation guide:
(i) Target concept: Visual confirmation of reducing sugar via alkaline copper tartrate (Benedict"s-type) reduction.
Minimum mechanism: Glucose must be present in solution; alkaline copper tartrate must be added *before* heating; thermal energy must drive redox reaction yielding Cu₂O; precipitate must form *in situ*, not pre-mixed or externally introduced.
(ii)Storyline: [Frame 0–2] Static shot: transparent test tube on desk, filled with colorless liquid (glucose). [Frame 3–4] Reagent (deep blue) poured into tube; liquid level rises, color transitions visibly to homogeneous blue. [Frame 5–6] Tube lifted and placed into water bath; immersion confirmed by water line and ambient steam/shimmer. [Frame 7–10] During heating, deep blue solution progressively develops discrete brick-red particles that settle downward; no color fade, no gas, no film formation: only sedimented precipitate.

Manual:
Experimental Procedure
1. Place a transparent test tube containing 1 mL of colorless glucose injection on desk.
2. Add 2 mL of deep blue alkaline copper tartrate reagent into the test tube.
3. Place test tube in water bath and heat for 3 minutes.
Observation of Experimental Phenomena
Deep blue solution turns to brick-red granular precipitate during heating.
Summary of Experimental Principles
Glucose reduces Cu²⁺ in alkaline tartrate complex to Cu₂O, forming brick-red precipitate — characteristic positive test for reducing sugars.

Prompt Grounding rubric:
level_1: No test tube present, or no glucose injection visible, or no alkaline copper tartrate reagent visible, or no water bath heating setup shown; none of the three core actions (placement, addition, heating) appear.
level_2: At least one core object present (e.g., test tube), and at least one core action occurs (e.g., liquid poured), but sequence is incorrect (e.g., heating before addition) or critical objects missing (e.g., reagent absent, glucose absent, water bath absent).
level_3: All three core objects present: transparent test tube, glucose injection (colorless liquid), alkaline copper tartrate reagent (deep blue liquid); all three core actions occur in correct order: (1) test tube with glucose placed on desk, (2) reagent added to test tube, (3) test tube placed into water bath; no object mislabeled or substituted.
level_4: All conditions for score 3 met, and spatial relationships preserved: test tube remains stationary on desk before addition; reagent poured directly into test tube (not beside it); water bath is visibly distinct (e.g., container with warm water, steam or uniform surface shimmer), and test tube is fully immersed or clearly positioned inside it; no object duplication, occlusion, or floating artifacts.
level_5: All conditions for score 4 met, and temporal continuity is flawless: no jump cuts between actions; each action begins only after prior action completes (e.g., pouring ends before heating begins); no object appears/disappears mid-sequence; viewpoint remains fixed and frontal throughout; no visual ambiguity in object identity or action boundaries.

Scientific and Causal Correctness rubric:
level_1: No color change observed; final mixture remains deep blue throughout; or red precipitate appears without prior heating; or precipitate forms before reagent addition.
level_2: Color change occurs but is inconsistent with Fehling's reaction: e.g., green/yellow/brown precipitate instead of brick-red; or precipitate appears while test tube is still on desk (no heating); or precipitate forms instantly upon mixing without delay.
level_3: Brick-red precipitate appears *only after* heating begins and *only within* the test tube; precipitate is granular/sedimented (not mirror-like film); color is distinctly brick-red (not orange, rust-red, or purple); no precipitate appears before heating or outside test tube.
level_4: All conditions for score 3 met, and causal fidelity holds: precipitate appears *during or after* heating phase (not before), and *only in heated test tube*; no precipitate in unheated control (if implied by context); no false phenomena (e.g., bubbling, gas evolution, boiling, or discoloration of reagent alone).
level_5: All conditions for score 4 met, and phenomenon is temporally precise: precipitate emerges *continuously* during heating (not instantaneously at start/end), remains stable during observation window, and shows no dissolution, fading, or re-suspension; no competing phenomena (e.g., cloudiness, layer separation, or color shift to black/grey).

Spatiotemporal Consistency rubric:
level_1: Test tube teleports between frames; reagent pours from off-screen with no visible source; water bath appears/disappears abruptly; lighting changes violently between shots; test tube deforms or fractures mid-sequence.
level_2: Object occlusion violates continuity: e.g., hand blocks test tube during pouring then vanishes; reagent stream discontinuous (gaps or jumps); heating action lacks spatial coherence (e.g., test tube shown outside water bath then instantly inside without motion).
level_3: All objects maintain consistent size, shape, and relative position across frames; no abrupt lighting shifts; no structural distortion (e.g., test tube stays cylindrical, no warping); motion is physically plausible (e.g., pouring follows gravity direction, no levitation).
level_4: All conditions for score 3 met, and temporal flow is uninterrupted: no frame drops, no stuttering motion, no duplicated or frozen frames; light/shadow remains consistent with fixed light source; reflections on test tube surface remain coherent with viewpoint.
level_5: All conditions for score 4 met, and spatiotemporal integrity is perfect: no parallax inconsistencies (e.g., background elements shift unnaturally relative to test tube); no inter-frame flicker or aliasing; motion trajectories are smooth and monotonic (e.g., pouring stream accelerates naturally, stops cleanly); no lens artifacts (e.g., chromatic aberration, vignetting) affecting object recognition.