Domain: Healthcare — Medicine
Target concept: Determination of pH in Injectables

Video generation prompt: Place a pH test strip and a standard color chart on the table. Using a transparent pipette containing 1 mL of glucose injection solution, drop the solution onto the pH test strip, allow it to stand for 1 minute, then compare the resulting color with the standard color chart to determine the pH range.

Evaluation guide:
(i) Target concept: Visual verification of pH via indicator-based colorimetry using standardized reagents and reference.
Minimum mechanism: Glucose injection must be aqueous, colorless, and capable of hydrating the indicator matrix; pH test strip must contain bromothymol blue/methyl red-type mixed indicators; color chart must encode discrete, non-overlapping pH intervals; human vision must resolve hue differences under neutral white light.
(ii)Storyline: Frame 1–2: Table surface establishes scene; pH test strip and standard color chart appear side-by-side, stationary, fully visible. Frame 3–4: Transparent pipette enters frame holding colorless liquid, positioned directly above test strip. Frame 5: Pipette tip contacts test strip surface; liquid transfers visibly. Frame 6–7: Test strip reactive zone uniformly darkens/lightens (e.g., yellow→green); no runoff or uneven absorption. Frame 8–10: Strip and chart remain simultaneously visible; final strip color aligns chromatically with one labeled chart block; no occlusion, motion, or lighting change disrupts comparison.

Manual:
Experimental Procedure
1. Place pH test strip and standard color chart side-by-side on table.
2. Hold transparent 1 mL pipette filled with glucose injection solution above test strip.
3. Dispense solution onto test strip; allow to stand for 1 minute.
4. Compare strip color to chart to determine pH range.
Observation of Experimental Phenomena
Glucose injection solution (colorless, transparent) wets pH test strip → reactive zone undergoes uniform, stable color change → final color matches one discrete block on standard color chart.
Summary of Experimental Principles
Glucose injection solution is isotonic and pH-stabilized (typically pH 3.5–6.5); pH test strips contain immobilized indicators that undergo protonation-dependent color change; comparison to calibrated color chart enables semi-quantitative pH determination per pharmacopeial standards.

Prompt Grounding rubric:
level_1: None of the required items (pH test strip, standard color chart, transparent pipette, glucose injection solution, table surface) are shown together in the scene.
level_2: Only some of the required items appear (for instance the pipette but not the color chart, or vice versa), or a substitute is used instead (an opaque dropper instead of a transparent pipette, a plain strip of paper instead of a labeled pH strip, or a non-standard reference chart), and no clear sequence of placing/dispensing/comparing takes place.
level_3: The pH test strip sits on the table, the standard color chart sits beside it on the same table, and a transparent pipette holding liquid is held above the strip; the pipette tip touches the strip, and the strip is then compared against the chart, in that order.
level_4: The strip and chart stay side by side and in frame throughout; the pipette is held roughly vertical while dispensing; the liquid visibly wets the strip's surface; nothing enters or leaves the frame partway through; no item is swapped out mid-scene for a different kind of object.
level_5: The pH test strip shows a printed scale and a distinct reactive zone; the color chart shows labeled pH values (e.g., 3.0–8.0) across clearly separated color blocks; the pipette is a clear cylinder marked with a 1 mL graduation; the liquid inside it is colorless and transparent; every item stays fully visible and in the same relative position on the table from the first frame to the last.

Scientific and Causal Correctness rubric:
level_1: No color change happens on the strip at all, or the color chart is missing while the strip's color does change, or the strip's final color falls somewhere the chart doesn't cover, or the liquid itself is visibly tinted, contradicting a colorless glucose injection solution.
level_2: The strip changes color but the chart never appears for comparison; or the strip is already colored before the liquid touches it; or the chart is present but its color blocks are nowhere near the strip's final hue (e.g., strip turns pale green while the chart only shows reds and oranges); or the liquid beads up and runs off the strip instead of soaking in.
level_3: After the liquid touches it, the strip's reactive zone changes color evenly and stays wet for at least 1 second; the resulting color falls somewhere within the range of hues shown on the chart's blocks, and the chart is upright and visible for the comparison.
level_4: The color change stays confined to the strip's reactive zone and doesn't bleed into the rest of the strip; the chart's blocks stay crisp, distinct bands rather than a blurry gradient; the strip's color holds steady once it develops rather than continuing to darken or fade; the final hue reads as belonging to one specific block, not stuck ambiguously between two.
level_5: The strip's final color and the matching chart block look like the same color side by side: same hue, same depth of color, same lightness; there's no discoloration at the edges of the strip, no glare or reflection washing out either the strip or the chart, and both stay clearly visible under the same lighting for the whole comparison.

Spatiotemporal Consistency rubric:
level_1: The strip appears already wet with no pipette contact shown; the chart pops in or out of the scene abruptly; the pipette's motion jumps, distorts, or breaks apart; the lighting changes drastically between frames; the tabletop's surface warps or loses its flat geometry.
level_2: The pipette touches the strip but no liquid transfer is visible; the strip's color changes before contact happens; the chart shifts position or angle relative to the strip between the dispensing and the comparison; the table's surface flickers or loses its texture momentarily; the shadows cast on the table swing to a different angle partway through with no clear cause.
level_3: The strip and chart stay side by side and flat on the table the whole time; the pipette approaches, touches down, and pulls away smoothly; the transition from dry to wet strip happens gradually rather than as a sudden cut; the color change spreads continuously across the reactive zone; nothing fully blocks the strip during the moments that matter.
level_4: The pipette tip never appears to poke into or through the strip's surface; the liquid spreads outward from the contact point at a steady, natural pace rather than snapping instantly to full coverage or stalling partway; the strip lies flat without curling or lifting as it gets wet; the chart never wobbles or drifts; nothing in the frame jumps or shears between one moment and the next.
level_5: There's no frozen or duplicated frame anywhere in the sequence; no blur hides the moment of contact, the wetting, or the color settling; the strip and chart both look like they sit at the same distance from the camera with no mismatched depth or perspective; the lighting stays even across the whole scene with no shifting gradient; the table, strip, and chart all look perfectly still and steady whenever nothing is supposed to be moving.