Domain: Engineering — Agricultural Engineering
Target concept: Observing the corn kernels by cutting them longitudinally reveals that the majority consists of white endosperm, with the embryo occupying only a small portion on one side, showing a distinct visual contrast.

Video generation prompt: Display a whole dried corn kernel placed on a flat surface. Use a sharp blade to longitudinally cut the corn kernel from the top to the bottom. Separate the two halves so that both cut faces are fully visible to the camera.

Evaluation guide:
(i) Target concept: Visual anatomical differentiation of maize kernel via longitudinal sectioning.
Minimum mechanism: Kernel must be biologically intact and dried (not soaked or cooked) to preserve structural integrity and native color contrast; blade must sever pericarp and internal tissues along true longitudinal plane (through germ notch) to expose unilateral embryo position; separation must not distort or displace tissues.
(ii)Storyline: [Frame 1–2] Whole kernel rests stably on flat surface. [Frame 3–4] Blade approaches and contacts kernel at apex. [Frame 5–7] Blade advances continuously along midline, splitting kernel. [Frame 8] Halves begin separating under mechanical release. [Frame 9–10] Halves settle side-by-side, fully static, with cut faces oriented toward camera; endosperm dominates central area of each face; embryo appears as discrete, smaller, pigmented mass on identical side of both halves. Perspective: Fixed frontal close-up; cut faces fully in focus; no occlusion; lighting reveals texture and contrast without glare.

Manual:
Experimental Procedure
1. Place a single whole dried corn kernel on a flat, neutral-colored surface.
2. Using a sharp blade, cut the kernel longitudinally from top to bottom in one smooth motion.
3. Gently separate the two halves and hold them side-by-side in view.
Observation of Experimental Phenomena
The two halves reveal a large, white, central tissue (endosperm) and a smaller, pigmented, compact structure (embryo) located unilaterally on one side of each half—creating clear visual contrast in size, color, and position.
Summary of Experimental Principles
Corn kernel anatomy: Endosperm constitutes the bulk of the kernel and stores starch; embryo is the living plantlet, occupying a small lateral region and differing in color, density, and morphology.

Prompt Grounding rubric:
level_1: No whole dried corn kernel is shown, or no blade appears; no cutting action begins; the kernel is never separated into two halves; no internal cut surface is ever visible on screen.
level_2: A whole dried corn kernel sits on a flat surface, but no blade is used and no cut is ever initiated, so no internal surface is exposed; or the kernel appears already split with no cutting action shown at all.
level_3: A whole dried corn kernel rests on a flat surface; a blade contacts the kernel at the top and begins cutting downward, but the cut stops partway or the kernel never fully separates into two halves: no internal cut surface becomes visible.
level_4: A whole dried corn kernel rests on a flat surface; a blade cuts longitudinally from top to bottom; the kernel separates into two halves that remain stationary and in view, with both cut faces oriented toward the camera, but at least one cut face is partly turned away, blurred, or blocked so its interior is not clearly visible.
level_5: A whole dried corn kernel rests on a flat surface; a single blade cuts longitudinally from top to bottom in one continuous pass; the two halves separate cleanly, come to rest side-by-side without any additional cutting or re-splitting, and remain stationary with both cut faces fully facing the camera, unobstructed and in focus for the remainder of the clip.

Scientific and Causal Correctness rubric:
level_1: The exposed tissue inside each half is a single uniform color throughout, with no lighter starchy region distinguishable from a darker germ region; no smaller structure is visible on either half.
level_2: Two visibly different regions appear inside the kernel, but they are the same color as each other; or the smaller region sits in the exact center of the half rather than toward one edge; or an equivalent smaller structure appears on both the left and right sides symmetrically, unlike a real corn kernel embryo.
level_3: Each half shows a large pale region occupying most of the cut face alongside a smaller, differently colored region near one edge; however, the smaller region sits on a different side in the two halves (e.g., left in one half, right in the other), or its shape looks stretched, split into pieces, or otherwise irregular for a corn embryo.
level_4: Each half shows a large pale central region (endosperm) alongside a smaller, distinctly colored (tan, yellow, or brown) region positioned on the same side in both halves (embryo), and the two regions are clearly different colors, but in at least one half the boundary between them is hard to make out because of glare, shadow, or the angle of the cut face.
level_5: Each half shows a large pale endosperm region occupying more than half the cut face, with a compact, oval, tan-to-brown embryo sitting only along one edge, the same edge in both halves; the border between endosperm and embryo is crisp and easy to see in both halves, and the size difference between the pale region and the embryo is unmistakable at a glance.

Spatiotemporal Consistency rubric:
level_1: The kernel or blade appears or disappears suddenly between shots; the halves are shown separated before any cutting motion has happened; the blade passes through the kernel without ever touching it; the two halves come apart unevenly and then appear whole again; the bench lighting abruptly shifts (e.g., bright to dark) between the cutting shot and the separated-halves shot with no visible cause.
level_2: The blade's cutting motion skips or restarts partway through the kernel; after separating, one half slides, spins, or flips position with no visible cause; the camera's focus or framing changes abruptly right as the halves separate.
level_3: The kernel stays in the same spot on the surface throughout; the blade moves in one consistent direction during the cut; the two halves separate along a single straight line and come to rest; a small slide or tilt right after separation is fine as long as the kernel does not jump or flip unnaturally.
level_4: The kernel remains fixed on the surface the entire time; the blade travels smoothly from top to bottom in one uninterrupted motion; the two halves separate cleanly and settle side by side with no bounce, spin, or sliding beyond a brief natural settling; the lighting and camera framing look the same before and after the cut; neither half chips, crumbles, or breaks apart beyond the single clean split.
level_5: The kernel shows no movement other than responding to the cut; the blade's path is smooth and stays aligned with the kernel's midline from start to finish; the two halves separate symmetrically and settle into stable, level, side-by-side positions with no drifting, tilting, or rotating afterward; the lighting, focus, and camera angle look completely unchanged across the whole clip; nothing flickers, warps, or looks distorted at any point.