Domain: Healthcare — Medicine
Target concept: Solubility of the drug

Video generation prompt: Place a transparent test tube on the desk, and add 0.1 g of aspirin powder into it. Then, add 10 mL of distilled water at room temperature, and stir using a magnetic stirrer at a speed of 300 r/min. Observe the dissolution of the drug.

Evaluation guide:
(i) Target concept: Visual demonstration of limited solubility via incomplete dissolution of a solid drug in water under standard conditions.
Minimum mechanism: Aspirin must exist as discrete solid particles distinct from solvent; water must remain optically clear; no chemical decomposition or solvation-induced phase change (e.g., gelation, precipitation of byproducts) may occur; dissolution kinetics must be slow enough that no appreciable mass transfer is visible within 10 s.
(ii)Storyline: Frame 1–2: Static shot of empty transparent test tube on desk. Frame 3–4: Hand or tool places white powder into tube (powder fully inside, no spillage). Frame 5–6: Liquid poured into tube (level rises visibly, no overflow). Frame 7–10: Stirrer bar rotates continuously inside liquid; particles remain individually resolvable and do not vanish, aggregate, or dissolve; liquid clarity unbroken; all events occur from fixed frontal/slightly angled viewpoint with full tube in frame and no occlusion.

Manual:
Experimental Procedure
1. Place transparent cylindrical test tube upright on desk.
2. Add 0.1 g white aspirin powder into tube.
3. Add 10 mL colorless distilled water.
4. Activate magnetic stirrer (bar inside tube) at steady rotation.
Observation of Experimental Phenomena
White aspirin particles remain visibly undissolved, suspended or settled at bottom; liquid phase stays transparent and colorless throughout; no complete dissolution occurs.
Summary of Experimental Principles
Aspirin (acetylsalicylic acid) has very low aqueous solubility (~3 mg/mL at 25°C); thus, 0.1 g in 10 mL water exceeds saturation limit, resulting in persistent solid phase.

Prompt Grounding rubric:
level_1: No transparent test tube present; or no aspirin powder visible; or no distilled water added; or magnetic stirrer absent; or none of the required objects (test tube, powder, liquid, stirrer) appear in the scene.
level_2: At least one required object appears (e.g., test tube OR powder OR water OR stirrer), but fewer than three are present; OR all four objects appear but in incorrect configurations (e.g., powder outside tube, water in beaker not test tube, stirrer not contacting liquid).
level_3: All four core objects are present and correctly associated: (1) transparent cylindrical test tube placed on desk surface, (2) white granular aspirin powder inside the tube, (3) colorless liquid filling part of the tube, (4) magnetic stirrer bar visibly rotating inside the liquid; sequence shows placement → addition → stirring.
level_4: All conditions for score 3 are met, AND the test tube remains stationary on desk throughout; powder is added before liquid; liquid is added before stirring begins; no extraneous objects (e.g., gloves, labels, other containers) occlude or replace required elements.
level_5: All conditions for score 4 are met, AND the test tube is upright and centered in frame; powder is fully contained within tube prior to liquid addition; liquid level reaches ~half to two-thirds of tube height; stirrer bar is fully submerged and continuously rotating without pause or reversal; no object enters/exits frame unexpectedly; all actions occur in fixed viewpoint with no camera repositioning.

Scientific and Causal Correctness rubric:
level_1: Aspirin powder dissolves completely and instantly upon contact with water; OR liquid changes color (e.g., turns blue, yellow, cloudy white); OR powder disappears before stirring begins; OR no state change occurs at all (e.g., powder remains dry and unmixed).
level_2: Powder remains visibly intact after stirring starts, but no discernible particle suspension or settling behavior is shown; OR liquid appears uniformly turbid without distinction between undissolved particles and clear phase; OR stirring occurs but zero interaction between bar and powder/liquid is visible.
level_3: After stirring begins, white aspirin particles remain visibly suspended or partially settled at bottom; liquid phase remains predominantly transparent and colorless; no complete dissolution observed during video duration; powder retains granular appearance and does not vanish or homogenize into solution.
level_4: All conditions for score 3 are met, AND particles are clearly distinct from liquid (no blending or haze); settling occurs gradually (particles move downward while liquid stays clear); no evidence of chemical reaction (e.g., fizzing, temperature-induced steam, color shift); all visual states match known low-solubility behavior of aspirin in water.
level_5: All conditions for score 4 are met, AND particles maintain sharp edges and discrete boundaries; settling motion is continuous and gravity-consistent (no floating, levitating, or erratic movement); liquid transparency is uniform across entire volume (no localized cloudiness except where particles reside); no optical artifacts (e.g., glare, bloom, chromatic aberration) obscure particle-liquid contrast.

Spatiotemporal Consistency rubric:
level_1: Test tube teleports between positions; or powder appears inside tube without being placed; or liquid appears without pouring motion; or stirrer bar rotates without visible drive mechanism or starts/stops abruptly mid-sequence; or lighting changes discontinuously (e.g., flash, total darkening).
level_2: One or more major spatiotemporal breaks: e.g., tube shifts laterally >1/3 its width between frames; stirrer bar jumps position without motion trail; powder vanishes then reappears; liquid level changes without visible addition; shadow direction flips between shots.
level_3: All objects maintain consistent spatial relationships: test tube remains fixed on desk; stirrer bar stays fully inside tube; powder stays inside tube; liquid surface remains horizontal; no object flickers, warps, or fractures; lighting and shadow remain stable in direction and intensity.
level_4: All conditions for score 3 are met, AND motion is physically plausible: stirrer rotation is smooth and continuous (no stroboscopic jumps or stutter); powder falls vertically into tube without lateral drift; liquid pours as cohesive stream without splashing or fragmentation; no interpenetration (e.g., stirrer passing through tube wall).
level_5: All conditions for score 4 are met, AND motion exhibits natural inertia: stirrer rotation accelerates smoothly from rest and maintains constant speed; powder descent decelerates slightly before impact; liquid meniscus forms and stabilizes without oscillation; no frame duplication, ghosting, or temporal aliasing; camera remains absolutely static with zero pan/tilt/zoom.