Domain: Healthcare — Clinical Laboratory Science
Target concept: Glucose Test (Benedict's Method)

Video generation prompt: Take 1 mL of urine from a diabetic patient, add 2 mL of Benedict's reagent, mix thoroughly, and heat in a boiling water bath for 5 minutes. Remove the test tube, cool to room temperature, and observe the color change of the solution.

Evaluation guide:
(i) Target concept: Visual verification of glucose detection in diabetic urine via Benedict's qualitative colorimetric assay.
Minimum mechanism: Urine must contain sufficient glucose to reduce Cu²⁺ → Cu₂O; Benedict's reagent must be an alkaline copper complex; heating in the boiling water bath is what drives and accelerates the reduction, so the color change should progress visibly during this step rather than being withheld until later; cooling afterward mainly lets any precipitate settle and stabilizes the color for observation, guarding against misreading hot-solution turbidity as the final result.
(ii)Storyline: [Frame 0–1] Urine (pale yellow liquid) dispensed into transparent test tube → [Frame 2] Blue Benedict's reagent added → [Frame 3] Vigorous swirling mixing → [Frame 4] Test tube immersed in actively boiling water bath (visible steam/bubbles); the blue color visibly shifts through green/yellow toward orange as the reduction proceeds under heat → [Frame 5] Tube removed once the color has developed toward orange/brick-red, held statically → [Frame 6] Tube placed on bench, fully still while any precipitate settles and the color stabilizes (cooling settles and stabilizes; it does not drive a further blue-to-color transition) → [Frame 7] Final frontal view of solution: homogeneous orange/brick-red suspension with no blue residue; all transitions must preserve object identity, spatial coherence, and causal timing; no off-screen actions; all key events must be fully visible within a fixed clinical-lab viewpoint.

Manual:
Experimental Procedure
1. Place 1 mL urine from diabetic patient into clean test tube.
2. Add 2 mL Benedict's reagent.
3. Mix thoroughly.
4. Heat in boiling water bath for 5 minutes.
5. Remove, cool to room temperature, observe color change.
Observation of Experimental Phenomena
Solution's color visibly shifts from blue through green/yellow/orange while immersed in the boiling water bath, reaching an orange-to-brick-red precipitate suspension by the time heating ends; cooling afterward settles the precipitate and stabilizes the color for observation rather than driving further color change.
Summary of Experimental Principles
Benedict's reagent contains copper(II) sulfate; reducing sugars (e.g., glucose) reduce Cu²⁺ to Cu⁺ during the heating step itself, forming an insoluble copper(I) oxide precipitate whose color intensity correlates with glucose concentration; cooling afterward is for safe handling and precipitate settling, not for driving the reaction.

Prompt Grounding rubric:
level_1: No urine sample, no Benedict's reagent, no test tube, and no boiling water bath appear; none of the sequence of drawing urine, adding reagent, mixing, heating, cooling, and observing color is shown.
level_2: At least one core object appears (e.g. a test tube or a liquid), but critical elements are missing: the urine volume isn't visually distinguishable as roughly 1 mL, the Benedict's reagent isn't present or doesn't look like roughly 2 mL, no mixing action is shown, there's no boiling water bath, no heating step, no cooling step, and no final look at the solution's color.
level_3: All core objects are present (the urine sample, Benedict's reagent, test tube, and boiling water bath), and the five key steps appear in the right order: about 1 mL of urine goes into the tube, about 2 mL of reagent is added, the tube is mixed, it's placed in the boiling bath and heated, then removed, cooled, and its color observed; but at least one step lacks clear visual confirmation, such as mixing that isn't visibly turbulent, heating without steam or a visible bath, or cooling with no time gap or ambient change.
level_4: Everything in score 3 holds, and the urine and reagent look like two visually distinct liquids in the same test tube in roughly the right proportions; all five steps happen in the right order with clear visual evidence: the transfer is visible, mixing shows a swirling motion, the boiling bath shows active bubbling and steam, the heating lasts long enough to be clearly sustained, cooling is shown through removal, a pause, and stillness before observation, and the final color is shown facing the camera; no step is skipped, reordered, or duplicated; only small flaws are allowed, like a brief flicker in the lighting, a soft-focus moment during cooling, or an unreadable label on the reagent bottle.
level_5: All core objects are present, clearly typed, and stay visible throughout: pale-yellow urine, clear-blue Benedict's reagent, a transparent cylindrical test tube, and a boiling water bath with visibly vigorous bubbling and steam; every step is executed with full visual clarity: precise liquid transfers with a visible change in liquid level, vigorous mixing with a visible swirl, clear immersion in the actively boiling bath, a deliberate removal followed by a sustained still period before observation, and the final color shown head-on with nothing blocking the view, with no step skipped, reordered, or ambiguous.

Scientific and Causal Correctness rubric:
level_1: No color change occurs at all (the solution stays blue throughout), or it changes to a color inconsistent with a positive glucose reaction (purple, black, or a color with no yellow/orange/red component); or a color change happens with no heat ever applied, or before the urine and reagent are even mixed.
level_2: A color change happens, but ends in the wrong final state: for example the solution stays blue with no reaction at all, or turns only a faint green with no further progression, or jumps straight from blue to brick-red with no green/yellow/orange stage visible in between; or the color changes before the tube is mixed, rather than after mixing and during/after heating.
level_3: The solution's color visibly shifts away from blue while the tube is in the boiling bath (consistent with the heat-driven reduction of Cu²⁺), and by the end of cooling and final observation the color is one of the valid Benedict's endpoints: green, yellow, orange, or brick-red; however, for urine from a diabetic patient the color should reach at least orange, so a final result stuck at green/yellow undershoots the expected intensity; or the suspension looks patchy or stratified rather than evenly mixed.
level_4: Everything in score 3 holds, and the color visibly progresses while the tube is in the boiling bath (moving through green/yellow/orange stages as heating continues), reaching orange or brick-red by the time the tube is removed or shortly after; cooling mainly lets any precipitate settle and the color stabilize, without reversing or washing out the color; the final suspension is homogeneous rather than showing undissolved clumps; one minor inconsistency is allowed, such as the precipitate not being perfectly evenly distributed in the last frame, or the color looking slightly desaturated under the lighting while still clearly orange/red.
level_5: The color change is visibly tied to the heating step: the solution stays blue right up until it enters the boiling bath, then progressively shifts toward orange/brick-red while immersed and boiling, and holds that color (or deepens slightly as any precipitate settles) through removal, cooling, and final observation with no reversal back toward blue or green; the final suspension is a vivid, saturated orange-to-brick-red, evenly distributed with no undissolved streaks; the color's timing is causally locked to the heating step, not to the cooling step, matching the fact that Cu²⁺ reduction is a heat-driven reaction.

Spatiotemporal Consistency rubric:
level_1: The test tube jumps from one location to another with no transit shown; the liquid inside vanishes and reappears; the boiling water bath appears or disappears mid-sequence; the lighting flips abruptly, e.g. from a bright bench to darkness in a single frame; the tube appears to shatter and then reform; or the mixing motion stops and restarts with a different swirl direction with no pause in between.
level_2: Several moderate breaks occur together: the test tube's position or tilt changes inconsistently between shots with no motion shown; the liquid level changes illogically between cuts; steam appears in only one frame and then vanishes; the tube is shown 'heating' with no steam or bubbling visible in the bath; the cooling step shows no time gap or change in ambient look; or the final color is observed while the tube still looks like it's steaming or fresh out of the bath.
level_3: One clear spatiotemporal flaw remains: the test tube rotates with no cause between the mixing and heating shots; steam is visible only at the very end of the heating step rather than throughout it; the cooling step is implied by a static shot with no visible transition (e.g., a hand removes the tube and the film cuts straight to the final color); or the final observation shows a hand still holding the tube instead of it resting for a steady view.
level_4: The test tube keeps the same size, tilt, and position across all shots; the liquid volume stays stable after the reagent is added; steam is visible continuously while the tube sits in the boiling bath; the bath itself keeps bubbling the whole time it's shown; the cooling step is shown as removal, then stillness, then a stable resting position; the final color is only shown once the tube is fully still; only a small flaw is allowed, such as a bit of camera jitter during mixing or a brief lens flare during the bath shot.
level_5: The test tube stays in a fixed position and orientation throughout; the liquid's surface stays stable and continuous through every transition; steam rises continuously and evenly the whole time the tube is in the boiling bath; the bath's bubbling looks persistent and natural rather than looping or freezing; the tube's removal from the bath is one smooth, uninterrupted motion; the cooling step shows a clearly unbroken period of stillness with lighting consistent with a room-temperature bench; the final observation shows the tube centered, upright, and completely still; every motion in the video is physically plausible and flows continuously from one step to the next.