Domain: Healthcare — Medicine
Target concept: Sterilized liquid bacterial culture, showing clarification occurring at time t after antibiotic exposure, followed by regrowth (re-turbidity) after transfer to fresh medium

Video generation prompt: A glass flask containing a turbid bacterial culture was administered an antibiotic, then shaken and observed over time. Subsequently, the liquid was transferred into a new flask containing fresh medium and the observation was continued.

Evaluation guide:
(i) Target concept: Antibiotic-mediated bacterial clearance followed by regrowth in permissive medium.
Minimum mechanism: Bacteria must be viable in original culture; antibiotic must be bactericidal/bacteriostatic; clarification requires reduction in suspended biomass; regrowth requires viable inoculum and nutrient availability.
(ii)Storyline: [Frame 0–2] Turbid culture in first flask (baseline state). [Frame 3–4] Antibiotic delivered (causal trigger). [Frame 5–7] Flask shaken (ensuring mixing/distribution). [Frame 8–9] Liquid transfers to second flask with fresh medium. [Frame 10–15] First flask shows progressive clarity (turbidity ↓). [Frame 16–25] Second flask remains clear briefly, then develops turbidity (turbidity ↑). All events occur from fixed frontal lab-view; no cuts; no POV shifts; flasks remain fully in frame; lighting constant; turbidity changes must be perceptible across consecutive frames without reliance on annotation.

Manual:
Experimental Procedure
1. Show glass flask with turbid liquid (an actively growing bacterial culture, not yet exposed to antibiotic).
2. Introduce antibiotic into flask (visible delivery).
3. Shake flask horizontally for several seconds.
4. Transfer entire liquid volume to new glass flask containing fresh sterile medium.
5. Observe both flasks: first shows progressive clarification; second shows delayed re-turbidity.
Observation of Experimental Phenomena
- Initial turbidity in first flask → decreases after antibiotic + shaking.
- Liquid transferred to second flask remains initially clear → becomes turbid after delay.
Summary of Experimental Principles
- Antibiotic kills or inhibits bacteria in original culture, causing clarification.
- Transfer to fresh medium without antibiotic allows surviving/resistant bacteria to regrow, restoring turbidity.

Prompt Grounding rubric:
level_1: No glass flask appears at all, or the liquid shown is not turbid/cloudy, or none of the required actions (antibiotic delivery, shaking, and transfer into a second flask) take place; the video bears no resemblance to a bacterial-culture-plus-antibiotic procedure.
level_2: A cloudy liquid in a single flask is shown, but at least one entire procedural step is missing outright (e.g., no delivery device or antibiotic ever touches the liquid, no shaking occurs, or the liquid is never moved into a second, separate flask), so the two-flask antibiotic procedure described in the prompt cannot be recognized.
level_3: All five procedural beats are present in the correct order (turbid liquid in the first flask, an antibiotic introduced into it, the flask shaken, the liquid moved into a second flask, and that second flask holding what is meant to be fresh medium), but at least one beat is only weakly cued, such as the antibiotic being added off-screen and only implied by a hand gesture, or the second flask's 'fresh medium' looking indistinguishable from plain water with no visible cue that it is a growth medium.
level_4: All five beats are unambiguous and in the correct order: the first flask starts visibly cloudy; a syringe, pipette, or dropper visibly delivers liquid into it; the flask is then shaken with a continuous back-and-forth or swirling motion; the entire liquid volume is poured from the first flask into a distinct second flask; and the second flask's contents are visually distinguishable from the first flask's original turbid liquid (different clarity, tint, or a visible label). Both containers are consistently rendered as glass flasks, not test tubes, beakers, or plastic bottles, and no extraneous objects or actions appear that the prompt does not call for.
level_5: Beyond everything required at score 4: the first and second flasks share the same glassware style, so the transfer clearly reads as moving liquid between two matching vessels rather than swapping in a random container; the antibiotic-delivery device is shown actually touching the liquid surface, not just hovering above it; the shaking uses one consistent motion style throughout (e.g., only side-to-side, never switching to swirling or flipping the flask upside down); the transfer is rendered as one continuous pour rather than a cut between two states; and the second flask's fresh medium is unmistakably marked as such, for instance a cap being removed just before the pour, a visible label, or a clearly different tint from the first flask's turbid liquid.

Scientific and Causal Correctness rubric:
level_1: The bacterial culture's turbidity does not meaningfully respond to the procedure: the first flask's cloudiness never decreases after the antibiotic is added, and/or the second flask's liquid never regains turbidity later; the video gives no visual evidence that the antibiotic affected the bacteria or that any bacteria survived to regrow in the second flask.
level_2: A turbidity change occurs but contradicts the underlying biology: for example, the first flask becomes more cloudy right after the antibiotic is added instead of clearer, or the liquid clears before the antibiotic is even introduced, or the second flask's liquid stays turbid the entire time with no clear stretch, erasing the distinction between the 'antibiotic present' and 'antibiotic absent' conditions.
level_3: The first flask does become visibly clearer only after the antibiotic is added and the flask is shaken, and the second flask's liquid does eventually regain turbidity, but the causal story is incomplete: for instance, the first flask's clarification happens instantly within a single frame rather than thinning out gradually, or turbidity returns in the second flask so quickly after the transfer that it looks as if the antibiotic were still active there, undermining the 'surviving bacteria multiply once the antibiotic is gone' logic.
level_4: The turbidity progression matches the intended biology from start to finish: the first flask's cloudiness fades gradually over several frames, and only after the antibiotic is added and the flask is shaken (never before); the second flask is visibly clear right after the transfer; and the second flask's liquid then gradually regains cloudiness over the later frames. Turbidity is shown strictly as cloudiness of the suspension itself: no floating clumps, settled sediment, or an unrelated color shift is used to stand in for a change in turbidity.
level_5: In addition to the 4-point requirements, the regrowth timing reads as biologically plausible in more detail: the second flask stays visibly clear for a noticeable stretch of frames right after the transfer (reflecting a lag before bacteria resume multiplying) rather than clouding up immediately; the turbidity levels are clearly graded across three states (most turbid: first flask at the very start; clearest: first flask after the antibiotic and second flask right after the transfer; intermediate: second flask once regrowth is underway); and there are no bubbles, glare, or reflections in either flask that could be mistaken for cloudiness.

Spatiotemporal Consistency rubric:
level_1: Severe breaks in physical continuity: the first or second flask is simply absent from a frame and then present again later with no pouring or carrying motion shown connecting the two states; the liquid inside a flask disappears or reappears without any visible pour; the shaking motion cuts straight to a completely different flask orientation with no transition; the background or camera framing changes entirely mid-sequence as if two different rooms had been spliced together; or the lighting shifts abruptly between bright and dark with no lamp, hand, or camera movement to explain it.
level_2: Noticeable but less extreme breaks: the shaking motion skips ahead so the flask jumps between widely different tilt angles instead of oscillating smoothly; the liquid stream during the transfer appears to hop from the first flask into the second rather than flowing continuously between them; the two flasks swap left-right positions partway through with no camera movement to justify it; or the liquid level in a flask changes abruptly between two frames with no shake or pour shown to account for it.
level_3: One brief inconsistency that does not affect which flask is which or the order of events (for example, the shaking motion pauses for less than half a second before resuming, the liquid's meniscus wobbles slightly out of step with the shaking for a moment, or the second flask's cap appears open in one frame and closed in the next with no hand shown moving it), while the positions of both flasks, the transfer direction, and the overall sequence of steps stay correct throughout.
level_4: The shaking is shown as a smooth, damped back-and-forth motion that settles naturally rather than stopping abruptly; the transfer shows one continuous, unbroken stream of liquid moving from the first flask into the second, with the liquid level in each flask changing in proportion to how much has moved; the first and second flasks keep the same relative position (e.g., first flask on the left, second on the right) for the entire sequence; and each flask's own cast shadow moves together with that flask as it is shaken or tilted, rather than staying frozen in place or flipping to the opposite side on its own.
level_5: On top of the 4-point criteria, small physical details sell the sequence as one continuous shot: the liquid surface shows a faint curved meniscus that shifts naturally with each shake instead of staying perfectly flat; the pour from the first flask into the second keeps a steady thickness without splashing or breaking into droplets; the framing of the background stays the same throughout with no sudden jump in camera position; and the glass of each flask visibly bends the view of whatever sits behind it, in a way that stays tied to that flask's own position as it moves.