Domain: Engineering — Computer Science
Target concept: Principle Demonstration of Push and Pop Operations in a Sequential Stack

Video generation prompt: This minimalist animation displays a vertical stack on a dark background. Colorful blocks labeled A, B, and C are sequentially pushed onto the stack from the top, and then sequentially popped off the stack.

Evaluation guide:
(i) Target concept: Visual demonstration of LIFO behavior via sequential push/pop operations on a vertical stack.
Minimum mechanism: Blocks must be discrete, labeled, and spatially ordered; vertical stacking must enforce top-only access; motion must unambiguously encode addition/removal at the top position; label identity must persist across states to verify ordering.
(ii)Storyline: Frame 1–2: Empty stack visible on dark background. Frame 3–4: Block A enters from top and settles at base position. Frame 5–6: Block B enters from top and settles directly atop A. Frame 7–8: Block C enters from top and settles directly atop B. Frame 9–10: Block C lifts upward and exits. Frame 11–12: Block B lifts upward and exits. Frame 13–14: Block A lifts upward and exits. All transitions require continuous vertical motion, fixed viewpoint, no occlusion of labels, and strict preservation of stack geometry, with visibility guaranteed for all labels at all times they are present.

Manual:
Experimental Procedure
1. Display a fixed vertical stack structure centered on dark background.
2. Sequentially push three colorful blocks labeled A, B, C from above onto the stack top (A first, then B, then C).
3. Sequentially pop the three blocks from the stack top (C first, then B, then A).
Observation of Experimental Phenomena
- Stack grows vertically by one block per push, always adding to topmost position.
- Stack shrinks vertically by one block per pop, always removing from topmost position.
- Labels A, B, C remain visible and upright at all times; their vertical order in stack is A (bottom), B (middle), C (top) after pushes; reversed during pops.
Summary of Experimental Principles
- Push operation adds element to top of stack; pop operation removes element from top — demonstrating LIFO (Last-In, First-Out) behavior.
- Sequential execution of push/pop enforces strict order dependency: insertion and deletion occur exclusively at the top, preserving stack integrity.

Prompt Grounding rubric:
level_1: No vertical stack structure is visible; blocks labeled A, B, or C are absent; no pushing or popping motion is shown; the background is not dark; the scene does not resemble the posted_prompt's stack animation.
level_2: A vertical stack-like column appears, but the A/B/C labels are missing or illegible; at most one block is shown entering or leaving the stack; the background is light or patterned rather than dark; push and pop motions are not both depicted.
level_3: A vertical stack sits on a dark background; three distinct blocks labeled A, B, and C are visible; blocks visibly enter the stack from the top (push) and later exit from the top (pop); however, label legibility, block color consistency, or vertical alignment breaks down at least once (e.g., a label becomes unreadable, a block's color changes between frames, or a block sits askew relative to the stack column).
level_4: All elements from score 3 are present AND blocks A, B, and C keep legible labels and stable, unique colors throughout; each block occupies a single, correctly aligned vertical position in the stack column with no overlap or gap; no extra or phantom blocks appear; labels stay upright and readable during all motion.
level_5: All elements from score 4 are present AND each block's entry motion ends precisely aligned atop the current stack (no overshoot or gap); each exit motion begins from the block's current position with no snapping or offset; no frame shows two blocks sharing the same stack slot outside of an intended stacking moment; every label stays fully visible and upright, without rotating or skewing, across all frames.

Scientific and Causal Correctness rubric:
level_1: There is no causal link between an action and a change in stack state; blocks appear or disappear without any push or pop motion; label order does not match the sequence of pushes and pops; LIFO ordering is broken in every instance (e.g., A is removed while C is still on the stack).
level_2: At least one push or pop occurs, but the result violates LIFO: a block enters from the side or bottom instead of the top; a block exits from the middle or bottom of the stack; the label order does not match the direction of motion; or a block vanishes without an exit motion.
level_3: Pushes originate from above and land on top of the current stack; pops originate from the top and exit upward; the push order is A then B then C, and the pop order is C then B then A; however, at least one moment breaks the physical plausibility of sequential occupancy: for instance, B settles into place before A has fully landed, or C exits while still overlapping B's position.
level_4: Every push adds strictly to the top of the stack and every pop removes strictly from the top; no block passes through or overlaps another outside of a landing/launching moment; the stack's height grows by exactly one block per push and shrinks by exactly one per pop; blocks A, B, and C keep their identity and correct position throughout; no transition breaks LIFO causality.
level_5: Everything required at the 4-point level holds, and in addition: the stack's height changes strictly in step with the actions shown, growing only during a push, shrinking only during a pop, and staying level during pauses; no block in transit overlaps a stationary block's slot except during its intended landing or launch; each pop is preceded by a fully settled stack in which the topmost block is exactly the one being removed; at no moment is it ambiguous which block currently sits on top.

Spatiotemporal Consistency rubric:
level_1: Blocks appear to jump between positions rather than move continuously; the stack's shape distorts or breaks apart; the lighting flickers or shifts abruptly; the background changes partway through; motion is jerky, with blocks freezing or skipping across several frames at once.
level_2: The stack or a block visibly scales, rotates, or shears while moving; a block changes size or color mid-motion; a shadow or highlight jumps to an inconsistent position; a block's motion path is broken, e.g., it vanishes and then reappears lower down instead of sliding continuously.
level_3: The stack stays centered and fixed; blocks travel along a single, consistent vertical line; no block disappears and reappears without a visible motion path; the lighting and shadow stay steady; however, a minor artifact occurs: e.g., one block's descent stutters briefly, or a momentary occlusion hides a label without otherwise breaking the stacking structure.
level_4: Every block keeps a consistent size, shape, and orientation; motion stays smooth and confined to the vertical axis; there are no abrupt lighting shifts, no distortion of a block's shape, and no dropped or duplicated frames; the base of the stack stays anchored in place; blocks only touch or overlap at the moments they are meant to be stacked.
level_5: Everything required at the 4-point level holds, and in addition: each block's motion visibly speeds up and slows down naturally at the start and end of its move rather than traveling at a constant speed; block motion shows no visually perceptible jitter or shake; the contact surface between stacked blocks lines up consistently across every frame where blocks touch; there is no flicker or shimmer along any block's edges or labels.