Domain: Humanities and Social Sciences — Geography
Target concept: Island Arc Landforms: Southeast Asian Malay/Sunda Arc (large, closely spaced islands fused into a continuous curved band) vs. American Aleutian Arc (small, widely spaced, point-like islands strung along a curved chain)

Video generation prompt: Satellite images of the Southeast Asian Malay Arc islands and the American Aleutian Arc islands are shown side by side. The left image shows the Southeast Asian Malay Arc islands, while the right image shows the American Aleutian Arc islands. The focus of the images is on the satellite imagery itself.

Evaluation guide:
(i) Target concept: Both the Malay/Sunda Arc and the Aleutian Arc are arcs whose curvature follows from the intersection geometry of a subducting slab with the spherical Earth (this small-circle geometric constraint is especially clean for arcs like these two, though continental-margin subduction elsewhere can yield comparatively straighter volcanic chains shaped more by the continental margin itself); so curvature alone cannot distinguish these two arcs; instead, island size and packing density create very different satellite-view silhouettes. This is observable via comparative satellite imagery of the Malay/Sunda Arc and the Aleutian Arc, both genuinely curved, but visually distinct.
Minimum mechanism: Both arcs sit above active subduction trenches and both curve. The Malay/Sunda Arc's islands (Sumatra, Java, Bali, Lombok, Sumbawa, Flores, Timor) are large, closely spaced landmasses that fuse visually into a near-continuous, convex, arch-like band with narrow straits. The Aleutian Arc's islands (Attu, Kiska, Adak, Unalaska, Kodiak) are far smaller and much more widely spaced, so in satellite view they read as a sparse, discontinuous chain of point-like islands strung along a curved trend rather than a solid arc.
(ii) Storyline: Frame 1–10: Static, simultaneous, full-frame view of two satellite panels locked in side-by-side configuration. Left panel renders the Malay/Sunda Archipelago as a continuous, convex band of large, closely spaced islands. Right panel renders the Aleutian Islands as a sparse, widely spaced chain of small, point-like islands along a curved trend. No camera motion, no annotation, no transition: pure comparative visual perception. Perspective is nadir (top-down), consistent illumination, natural color, no occlusion. Visibility requires unambiguous differentiation: a dense, fused arc band on the left vs. a sparse, dotted island chain on the right.

Manual:
Experimental Procedure
1. Display two high-resolution satellite images side by side: left panel = Southeast Asian Malay/Sunda Arc; right panel = American Aleutian Arc.
Observation of Experimental Phenomena
2. Left image shows large, closely spaced islands (Sumatra, Java, Bali, Lombok, Sumbawa, Flores, Timor) fused into a continuous, convex arc band with narrow straits between them; right image shows much smaller islands (Attu, Kiska, Adak, Unalaska, Kodiak) spaced far apart along a curved trend, separated by wide stretches of open ocean.
Summary of Experimental Principles
3. Both arcs are curved because each traces a subduction trench where a rigid oceanic slab meets the spherical Earth's surface, so curvature alone does not distinguish them. What differs is island size and packing density: the Malay/Sunda Arc's larger, closely fused islands read visually as one continuous curved band, while the Aleutian Arc's smaller, widely spaced islands read as a loose, dotted chain along a similarly curved trend.

Prompt Grounding rubric:
level_1: No side-by-side satellite pair appears: only one island group is shown, or neither the Malay/Sunda islands nor the Aleutian islands are visible, with no left/right framing indicating Malay/Sunda on the left and Aleutian on the right.
level_2: Both island groups appear but are not arranged side by side (e.g., stacked, overlapping, or shown at different times), or the left/right placement is swapped (Aleutian on the left, Malay/Sunda on the right).
level_3: Side-by-side panels correctly place the Malay/Sunda islands on the left and the Aleutian islands on the right, but at least one side fails to read as an island group at all, e.g., one panel shows a single unbroken landmass, open ocean with no islands, or a random scatter with no coherent curved trend.
level_4: Correct left/right placement, and both panels show genuine curved island trends, but the two are not visually differentiated as required: e.g., the left panel's islands are small and widely spaced like the right panel's, or the right panel's islands are large and closely fused like the left panel's, so the size/density contrast is lost.
level_5: Side-by-side satellite imagery with the Malay/Sunda islands on the left and the Aleutian islands on the right; the left panel shows large islands closely spaced into a continuous, fused curved band with narrow water gaps between them; the right panel shows small, point-like islands widely spaced along a curved trend with broad open-ocean gaps between them; no occlusion, distortion, or left-right mislabeling.

Scientific and Causal Correctness rubric:
level_1: Neither panel shows any convincing sign of real subduction-zone volcanism or trench-linked positioning: e.g., both are drawn as flat, non-volcanic landmasses, or as islands scattered with no relation to any curved trench system at all.
level_2: One panel shows recognizable volcanic-island character consistent with an active arc (e.g., cone- or crater-like island profiles sitting along a curved trend), but the other panel's islands show no volcanic character and no curved-trend relationship to any trench, e.g., flat, deltaic, or reef-like terrain with no volcanic form.
level_3: Both panels show islands with some plausible volcanic character, but at least one arc's convex bulge faces the wrong way relative to its own trench, e.g., the Malay/Sunda islands bulge away from the Sunda Trench toward the Sunda Shelf instead of toward the trench itself, or the Aleutian islands bulge toward the Bering Sea instead of toward the Pacific-plate/trench side.
level_4: Both arcs' islands show volcanic character and bulge in the tectonically correct direction relative to their own trench, but a secondary detail is off: e.g., the Malay/Sunda islands show no visible volcanic cone or crater shapes despite this arc's well-known stratovolcano chain, or the Aleutian islands appear as smooth, non-volcanic humps inconsistent with this arc's basaltic-andesitic volcanic cones.
level_5: Both panels show volcanic-island forms (visible cone- or crater-like profiles) bulging in the tectonically correct direction for their own trench: the Malay/Sunda islands bulge toward the Sunda Trench, their convex side facing the Indian Ocean, consistent with the Indo-Australian plate subducting beneath the Sunda Shelf, and the Aleutian islands bulge toward the Aleutian Trench, their convex side facing the Pacific, consistent with oceanic-oceanic subduction of the Pacific plate beneath the North American plate; no volcanic or orientation detail contradicts either arc's real tectonic setting.

Spatiotemporal Consistency rubric:
level_1: A severe break in continuity occurs in either panel: islands in the Malay/Sunda group or the Aleutian group visibly jump to a new position, merge together, or disappear partway through the sequence; or the ocean's sun-glint pattern swaps to the opposite side of one panel while the other panel's glint pattern stays fixed.
level_2: Moderate inconsistency: the two panels diverge in resolution, color balance, or contrast partway through, undermining direct comparison of island size and spacing; or one panel's framing zooms, pans, or rotates while the other stays fixed on the same coastlines.
level_3: Minor inconsistency only: e.g., a faint difference in cloud cover appears over the Malay/Sunda islands versus the Aleutian islands partway through, or one panel's coastlines settle into their final position a couple of frames later than the other, but every island in both panels stays visible and in place throughout.
level_4: Both panels hold an identical fixed nadir framing on their respective island group from first frame to last, with matching brightness/color treatment and no zoom, pan, or rotation in either panel; every island of the Malay/Sunda chain and every island of the Aleutian chain stays visible and in the same relative position across all frames.
level_5: All conditions for score 4 are met, and in addition the ocean texture, cloud cover, and sun-glint pattern within each panel stay visually uniform for that panel's whole duration, with no visible flicker, shimmer, or popping in/out of any island or coastline in either the Malay/Sunda or Aleutian imagery.