Domain: Engineering — Computer Science
Target concept: Breadth-First Search (BFS) of a Graph Demonstration

Video generation prompt: Create a simple animated 2D graph on a white background with 6 labeled nodes (A-F) connected by lines in this fixed layout: A-B, A-C, B-D, B-E, C-F. Animate a Breadth-First Search traversal of the graph starting at node A. Display a queue visualization beside the graph that updates as the traversal runs. Use one distinct highlight color to mark the node currently designated as the traversal's starting point, a second distinct visual state for nodes that have entered the queue, and a third, faded or muted visual state for nodes that have finished being processed. Keep the camera fixed and unmoving for the whole animation.

Evaluation guide:
(i) Target concept: Breadth-First Search as a layer-wise graph traversal algorithm governed by FIFO queue discipline.
Minimum mechanism: Node labeling must be explicit and persistent; adjacency must be statically encoded in the six edges (A-B, A-C, B-D, B-E, C-F); the queue must enforce strict first-in-first-out ordering; the animation must use three visually distinguishable states (one for the current source/frontier, one for nodes waiting in the queue, and one faded/muted state for fully processed nodes), with state changes triggered only by queue events (enqueue, dequeue), not by arbitrary timing.
(ii)Storyline: Frame 1: White background + static graph (A-F, labeled, connected as specified) + empty queue. Frame 2: A takes on the source highlight state; queue shows [A]. Frame 3: A is dequeued; B and C take on the frontier/queued state; queue updates to [B,C]. Frame 4: B is dequeued; D and E take on the frontier/queued state; C is dequeued; F takes on the frontier/queued state; queue updates to [D,E,F]. Frame 5: D, E, F are dequeued one by one; each fades to the processed/muted state in sequence; queue empties to []. All transitions are viewable from a fixed frontal 2D perspective; no camera movement; no occlusion; all elements remain fully visible throughout.

Manual:
Experimental Procedure
1. Display white background.
2. Render six circular nodes labeled A, B, C, D, E, F in fixed positions; connect A-B, A-C, B-D, B-E, C-F.
3. Give node A the source highlight state.
4. Add A to the queue visualization (e.g., [A]).
5. Dequeue A -> give B and C the frontier/queued state -> add B and C to the queue ([B,C]).
6. Dequeue B -> give D and E the frontier/queued state -> add D and E to the queue; dequeue C -> give F the frontier/queued state -> queue becomes [D,E,F].
7. Dequeue D, E, F in order -> fade each to the processed/muted state upon dequeue.
Observation of Experimental Phenomena
- Node A takes the source highlight state first, then fades to the processed/muted state after being dequeued.
- Nodes B and C take the frontier/queued state together after A is dequeued, then fade to the processed/muted state after being dequeued themselves.
- Nodes D, E, F take the frontier/queued state only after both B and C have taken it, then fade to the processed/muted state after being dequeued.
- Queue displays exact FIFO sequence: [A] -> [B,C] -> [D,E,F] -> [].
Summary of Experimental Principles
Breadth-First Search explores all nodes at the current depth (layer) before moving to the next depth level. It uses a queue to manage visit order: enqueue the starting node; while the queue is non-empty, dequeue a node, process it (mark it visually), and enqueue all of its unvisited neighbors. The visualization maps queue state and node visual state to layer depth: source highlight = root, frontier/queued state = current layer being discovered, processed/muted state = fully visited.

Prompt Grounding rubric:
level_1: No graph visualization appears; no labeled nodes (A-F) present; no lines connecting nodes; no queue display; no visual state changes occur on any node; background is not white.
level_2: A static white background is present, and at least three unlabeled geometric shapes appear, but none are labeled A-F; no connected lines between them; no queue visualization; no node ever changes its visual state.
level_3: A white background is present; six labeled nodes (A, B, C, D, E, F) appear; lines connect at least three pairs of nodes; a queue visualization appears (e.g., a horizontal list or vertical stack) somewhere on screen; node A takes on a distinct highlight state at the start; at least one other node later takes on a second, visually distinct state; at least one node visually fades or mutes at some point.
level_4: White background present; all six nodes labeled A-F appear; the five edges match the specified topology (A-B, A-C, B-D, B-E, C-F) with no missing or extra connections; the queue visualization is continuously visible beside the graph and its listed contents change over time; node A takes on its highlight state from the first frame; over the course of the video, nodes visibly pass through three distinguishable states (a starting/frontier state, a queued state, and a faded/processed state), using a consistent visual scheme; no extraneous labels, shapes, or objects appear.
level_5: White background present; exactly six uniformly shaped nodes labeled A-F appear; all edges exactly match the specified topology with none missing, extra, or misdrawn; the queue box sits beside the graph, stays legible, and always lists node labels (not just marks or dots); node A shows its highlight state from the first frame of the animation; three clearly distinguishable, consistently applied visual states are used across the video for the starting/frontier, queued, and processed conditions; no flicker, overlapping labels, occlusion, or mislabeling occurs anywhere in the video.

Scientific and Causal Correctness rubric:
level_1: No meaningful correspondence exists between node visual states, the queue's contents, and BFS logic; nodes change state in a way unrelated to adjacency or queue order; the queue display and the node states directly contradict each other.
level_2: Node A takes on the source state, but no true neighbor of A (B or C) ever changes state; or a node that is not directly connected to A (such as D, E, or F) changes state before or instead of B or C; the queue's listed contents do not match which nodes have actually changed state; there is no visible link between which node is at the front of the queue and which node changes state next.
level_3: Node A takes on the source state first; both of its true neighbors, B and C, take on the frontier state before any of D, E, or F change; the queue shows A first, then B and C being added, but D, E, or F change state out of order relative to the queue (e.g., before both B and C have left the front of the queue, or in a different order than the queue implies).
level_4: Nodes change state strictly by BFS layer: A (layer 0) changes first; B and C (layer 1, A's true neighbors) change together as a group before D, E, or F begin changing; D, E, and F (layer 2) do not begin changing until both B and C have already changed; the queue empties in an order consistent with FIFO processing (A, then B and C, then D, E, and F); each node fades to the processed state only after it has left the front of the queue; no node changes to a later-layer state before an earlier one, and no node is skipped.
level_5: Every visual state change is tied directly to a queue event: A takes the source state and enters the queue; when A is dequeued, B and C (and only B and C) simultaneously take the frontier state and enter the queue; when B is dequeued, D and E (and only D and E) take the frontier state; when C is dequeued, F takes the frontier state; each node fades to the processed state in the same moment it leaves the front of the queue; no node is ever shown in two states at once, no node changes state out of its correct adjacency (e.g., D never changes before B has been dequeued), and the entire sequence unambiguously matches the specified BFS layering.

Spatiotemporal Consistency rubric:
level_1: Nodes, edges, or queue entries visibly teleport or jump position between frames with no drawing or moving animation shown; two copies of the same node label (e.g., two A's) appear at once; the white background flashes or changes hue.
level_2: Node positions stay fixed, but the connecting lines are drawn or redrawn after the nodes have already appeared, visibly out of sync; queue entries pop in or out abruptly with no insertion or removal animation; a node's state change appears as a full-screen flash rather than a change localized to the node itself; a node disappears and later reappears mid-sequence.
level_3: Nodes stay in the same screen position throughout; the six connecting lines are drawn once near the start and never redraw or jump afterward; the queue box stays in one place on screen while its listed labels change; state changes are visible at the node itself rather than as a background-wide effect; no node disappears or duplicates, though the exact instant a state change appears may look slightly abrupt.
level_4: Node positions relative to one another stay identical for the entire video; every line stays attached to the same two node labels with no detachment or redrawing; the queue box keeps the same size, location, and alignment (only its listed contents change); each state-color transition at a node looks clean, with no stray fragments or flicker; nothing in the graph appears to float, tilt, or shift as if the camera moved.
level_5: Node positions, line endpoints, and the queue box are visibly static across the whole video with no detectable drift; every state change at a node is shown fully applied in one step rather than partially (no node shown half in one state and half in another); no frames appear duplicated, skipped, or stuttering; the fade to the processed state spreads evenly across the whole node shape rather than unevenly across one side; the white background shows no flicker, gradient, or shadow appearing anywhere on screen.