Domain: Humanities and Social Sciences — Sport
Target concept: The triple jump stride rhythm is characterized by the sequence jump - leap - jump, referred to as the triple jump stride rhythm. The first step lands on the takeoff leg, the second step lands on the swinging leg, and the third step involves both feet landing simultaneously, exhibiting distinct stride characteristics.

Video generation prompt: A long jumper sprints, takes off with one leg, completes a standard and complete triple jump, and lands with both feet in the sand pit. The entire movement is clearly and smoothly presented.

Evaluation guide:
(i) Target concept: Triple jump as a rhythmically segmented horizontal jumping sequence governed by strict leg alternation and terminal symmetry.
Minimum mechanism: Human bipedal locomotion with unilateral force generation enabling three discrete, causally chained aerial phases, where each landing directly enables the next takeoff via elastic recoil and neuromuscular coordination; sand pit must serve as unambiguous, deformable endpoint confirming final bilateral impact.
(ii)Storyline: Sprint → single-leg takeoff → first flight → first contact (takeoff leg only) → second flight → second contact (swinging leg only) → third flight → third contact (both feet simultaneously in sand). Causal transitions require visible continuity: takeoff impulse determines first flight arc; first landing posture and timing enable second takeoff; second landing sets up final takeoff angle and height; final flight trajectory must descend into sand with bilateral foot alignment visible at frame of impact. Perspective must be frontal or oblique side view (not overhead or extreme low angle) to unambiguously resolve foot identity, contact timing, and sand interaction. All events occur in same continuous shot with fixed viewpoint and stable lighting.

Manual:
Experimental Procedure
1. Athlete sprints horizontally toward sand pit.
2. Takes off from one leg (takeoff leg) into first flight phase (jump).
3. Lands on same takeoff leg (first contact).
4. Immediately rebounds into second flight phase (leap), landing on opposite (swinging) leg (second contact).
5. Immediately rebounds into third flight phase (final jump), landing with both feet simultaneously in sand pit (third contact).
Observation of Experimental Phenomena
- First contact: single foot (takeoff leg) on ground.
- Second contact: single foot (swinging leg) on ground — opposite limb from first contact.
- Third contact: both feet touching sand at identical time — no stagger, no sequence.
- Flight-phase distances follow standard triple-jump proportions: the swinging-leg leap (step) phase is typically the shortest of the three, while the takeoff-leg jump and the final bilateral jump cover comparably longer distances.
Summary of Experimental Principles
Triple jump stride rhythm = jump (takeoff leg landing) → leap (swinging leg landing) → jump (bilateral landing); biomechanically defined by alternating leg dominance followed by symmetrical landing.

Prompt Grounding rubric:
level_1: No sprint approach toward a sand pit is visible, no single-leg takeoff occurs, no sand pit appears anywhere in frame, and no two-foot landing is shown: the clip shows at most an isolated running pose or an unrelated jump with no pit present.
level_2: Only one or two of the four setup elements appear (a sprint approach, a single-leg takeoff, a sand pit in frame, a two-foot landing), for example the athlete sprints and takes off on one leg but the clip ends before any sand pit appears, or a sand pit and two-foot landing are shown with no preceding sprint or single-leg takeoff; OR all four setup elements are present but fewer than two separate contact events (ground touches after a flight phase) can be told apart from each other.
level_3: All four setup elements appear somewhere in the clip (sprint approach, single-leg takeoff, sand pit, a two-foot landing) AND at least two of the three expected contact events are clearly distinguishable from each other, but the sequence is incomplete in one of these ways: only two contacts occur before the clip ends, all three contacts blur into a single touch-down that cannot be separated into distinct events, or all three contacts are distinguishable yet the final two-foot landing clearly touches down outside the sand pit's boundary or squarely on its rim rather than on the pit surface.
level_4: All four setup elements are present AND three separate contact events are clearly distinguishable in temporal order (first, second, third) AND the final contact is a two-foot landing that touches down fully inside the sand pit surface, but one minor framing flaw remains that does not obscure any contact or the takeoff, e.g., the sprint approach is partly cropped at the edge of frame, or the far boundary of the pit is cut off.
level_5: All four setup elements are present and fully within frame (an unobstructed sprint approach, a clearly visible single-leg takeoff, a fully framed sand pit, a two-foot landing) AND three separate contact events are unambiguously distinguishable in temporal order AND the final contact shows both feet touching the sand at once, fully inside the pit surface, with no contact event missing, duplicated, or cut off by framing anywhere in the shot.

Scientific and Causal Correctness rubric:
level_1: The three contact events cannot be clearly told apart in sequence, or a landing bears no visible relationship to the flight arc that preceded it, breaking the causal chain from takeoff to landing. This applies regardless of how many of the three leg-identity criteria (first contact on takeoff leg, second on opposite/swinging leg, third bilateral) might otherwise appear satisfied.
level_2: All three contact events are visible, sequentially distinguishable, and each landing visibly follows from the flight arc that preceded it, but at most one of the three criteria is satisfied (first contact on the takeoff leg, second contact on the opposite/swinging leg, third contact with both feet together), for example none of the three hold, or only one holds while the other two fail.
level_3: All three contact events are visible and sequentially distinguishable, AND exactly two of the three criteria are clearly satisfied while exactly one fails (e.g., the first and third contacts are correct but the second lands on the same leg as the first, or vice versa), with each landing still visibly following from the flight arc that preceded it.
level_4: All three criteria are satisfied (first contact on the takeoff leg, second contact on the opposite leg, third contact with both feet together) AND the athlete's horizontal position advances continuously forward across all three flight phases with no backward movement or stall AND body posture in each phase broadly matches triple-jump technique (upright carriage into the first jump's landing, an extended reaching leg into the leap's landing, a forward-flexed tuck into the final jump's landing), but one posture or progression cue is ambiguous or hard to read.
level_5: All three criteria are satisfied AND horizontal progress is unambiguous and continuous across all three phases with no backward regression AND the leap phase's horizontal distance does not visibly exceed either the first jump's or the final jump's distance, consistent with standard triple-jump proportions, AND body posture, arm action, and knee drive in every phase clearly match standard triple-jump technique, with no ambiguity about which leg lands when or how the sequence progresses forward.

Spatiotemporal Consistency rubric:
level_1: A severe spatiotemporal break occurs: the athlete or the sand pit jumps to a different position or orientation between phases with no continuous motion connecting them, the athlete's body disappears and reappears, a limb visibly detaches or fuses into another body part, the clip freezes and restarts partway through the sprint-to-landing sequence, or the scene lighting changes abruptly with no visible cause (e.g., a sudden shift between bright and dark).
level_2: A noticeable but partial break occurs: e.g., the sand pit's edges or the runway's position shift between one contact and the next even though the athlete's overall motion continues, the athlete's torso or hip rotation snaps to a different orientation between two contacts with no connecting motion shown, one of the three flight arcs cuts abruptly into the next contact with a visible jump in the athlete's position rather than a continuous trajectory, or a shadow's direction changes between phases with no corresponding change in the light source.
level_3: Only minor, recoverable irregularities appear: e.g., brief jitter in a limb's motion during one flight phase, a small mismatch between where the final foot lands and where the resulting sand displacement appears, or a short pause between the leap and the final jump, but the sand pit, runway, and camera framing stay in the same fixed position throughout, and the athlete's path from sprint through all three contacts can be followed continuously with no sudden repositioning or missing segments.
level_4: The sand pit, runway, and camera framing remain fixed and consistent for the entire sequence, motion from sprint through all three contacts is continuous with no gaps or resets, lighting stays consistent throughout with shadows tracking a single steady light source, and the final bilateral landing's sand disturbance (impact, displacement, settling) looks physically consistent with that foot strike, but one small flaw remains, such as slight asymmetry in the sand kicked up at that landing or brief motion blur during the fastest part of a flight phase, without it being enough to obscure which contact is occurring.
level_5: No spatiotemporal flaws are present: camera framing and the sand pit's position stay fixed for the entire sprint-to-landing sequence, lighting shows no fluctuation and shadows show no inconsistency relative to a single steady light source, every limb traces a smooth, physically continuous path from takeoff through all three contacts with no jumps, freezes, or pose snapping, the first two contacts (on the runway) show no anomalous sand disturbance, and the final bilateral landing's sand disturbance matches the timing and force of that landing exactly with no delayed or premature spray.