Domain: Natural Science — Physics
Target concept: Diode

Video generation prompt: A battery power supply, an LED lamp, a diode, and a single-pole switch are connected in series on the table to form a closed circuit. Pressing the single-pole switch causes the LED to light up; then, opening the switch, reversing the polarity of the diode, and closing the switch again completes the circuit.

Evaluation guide:
(i) Target concept: Unidirectional conduction of semiconductor diodes demonstrated via LED illumination state as proxy for current flow.
Minimum mechanism: LED requires forward-biased current to emit light; reversing diode polarity prevents circuit completion under DC supply; switch provides deterministic control of circuit continuity.
(ii)Storyline: Frame sequence must show: (1) static setup with all four labeled objects in series on flat surface, (2) hand presses switch → LED illuminates, (3) hand releases switch → LED extinguishes, (4) hand rotates diode 180° around its long axis while switch remains open, (5) hand presses switch again → LED remains unlit; all events occur from fixed frontal tabletop view, with no occlusion violating spatial continuity (e.g., hand never fully hides both diode ends simultaneously during rotation), and no lighting or perspective shift between phases.

Manual:
Experimental Procedure
1. Place battery, LED lamp, diode, and single-pole switch in series on table, connected by wires.
2. Close switch: observe LED lights up.
3. Open switch, reverse diode polarity, then close switch again: observe LED remains unlit.
Observation of Experimental Phenomena
- LED emits light only during first switch closure (forward-biased diode).
- LED emits no light during second switch closure (reverse-biased diode).
Summary of Experimental Principles
- Diode allows current flow only in one direction (forward bias); blocks current in reverse bias.
- LED is a type of diode that emits light when forward biased.

Prompt Grounding rubric:
level_1: Fewer than three of the four required components (battery pack, LED lamp, diode, single-pole switch) are visible, or the visible components are not wired into one continuous loop on the tabletop, or the switch is never touched or operated at any point in the clip.
level_2: All four components are visible on the tabletop, but the wiring is broken or forms parallel branches rather than a single loop (e.g., a gap between the diode and the LED, or two separate wire paths), or the switch is shown but neither a press-and-close nor a release-and-open action is depicted.
level_3: Battery, LED, diode, and switch are wired end-to-end into one loop with visible connecting wires; the switch is pressed closed once and later released open once, and the diode is turned around by hand somewhere between those two switch actions, with the press, release, and diode turn happening in that order.
level_4: Everything required for score 3 is shown, and in addition the diode's reversal is unmistakable: the banded (cathode) end sits on the opposite side of the loop after the turn compared with before; and the switch's closing and opening are each shown as a distinct mechanical motion, with the two contacts visibly coming together to close and visibly separating to open, rather than an implied or off-screen click.
level_5: Everything required for score 4 is shown, and in addition the wire loop stays intact in every frame (no gap ever opens between battery, diode, LED, or switch other than the deliberate lifting of the diode to turn it), the diode is turned around only after the switch has fully opened rather than while the switch is still mid-motion, and the second closing of the switch follows the diode's turn without any component being lifted off the table or removed from view in between.

Scientific and Causal Correctness rubric:
level_1: The LED never lights in either trial, or it lights while the diode is reversed, or it stays lit continuously through both trials regardless of the switch, or it emits a color other than the single expected LED color, or it appears lit without any visible path back through the diode and switch to the battery.
level_2: The LED lights in only one of the two trials, but that lit trial is the reversed-diode one rather than the forward one; or it lights in both trials; or in either trial it turns on before the switch closes or stays lit after the switch opens.
level_3: The LED lights only while the switch is closed and the diode sits in its original (forward) orientation, and it stays dark through the whole second trial after the diode is turned around; it produces no light while the switch is open in either trial; and its color stays the same single hue across both trials.
level_4: Everything required for score 3 holds, and in addition the LED shows no partial glow or flicker at all during the reversed-diode trial (it is fully dark, not dim), the LED's lit appearance during the forward trial is steady rather than pulsing, and the LED's brightness change tracks the switch closely: it comes on within roughly 1–2 frames after the switch closes and goes dark within roughly 1–2 frames after it opens, without a lag long enough to suggest it is running on its own timer rather than responding to the switch.
level_5: Everything required for score 4 holds, and in addition the LED's on/off state is explained only by the diode's orientation and the switch's position (no stray light or reflection could be mistaken for the LED itself lighting), and at no point in either trial does the LED appear lit while the diode is reversed, nor lit while the switch is open.

Spatiotemporal Consistency rubric:
level_1: Any component instantly jumps to a new position or vanishes and reappears (for example the switch appears in a different spot, or the diode disappears from the loop without the hand removing it), the wire path visibly snaps apart and then knits itself back together on its own, the scene's overall brightness swings from dark to bright with no switch action or other visible cause, or the camera cuts to a different angle partway through the clip.
level_2: The camera holds one fixed angle throughout, but some object still moves unnaturally (the diode spins in place with no hand touching it, or the LED drifts off the tabletop), or a wire segment visibly stretches or compresses without being touched, or the scene's overall brightness jumps in a single step rather than changing smoothly when the LED turns on or off.
level_3: The camera stays at one fixed tabletop angle for the whole clip; every motion is caused by a hand entering the frame to press the switch, release it, or turn the diode; no component drops out of view and reappears elsewhere; the wire loop stays joined at every point except where the diode is deliberately lifted and reinserted; and the room's overall lighting does not swing or reverse on its own.
level_4: Everything required for score 3 holds, and in addition the hand covers the diode only for the moment it is actually being turned (it never freezes mid-turn or hides both of the diode's ends for longer than the turning motion takes), the switch's two contacts approach and separate at a steady, continuous pace rather than jumping straight from open to closed, and the footage runs smoothly frame to frame with no visible warping of any object's shape.
level_5: Everything required for score 4 holds, and in addition the battery, diode, LED, and switch keep the same left-to-right order along the loop in every frame; the spacing between neighboring components never visibly grows or shrinks; no component drifts sideways or vertically out of its original line; and the hand's position relative to the wires stays physically consistent: it never appears to pass behind a wire in one frame and in front of that same wire in the next.