Domain: Humanities and Social Sciences — Economics
Target concept: Use a pie chart to intuitively present the market shares of a perfectly competitive industry.

Video generation prompt: To illustrate this, create a simple industry market share pie chart showing the market shares of companies (A, B, C, D, E) to represent a perfectly competitive industry.

Evaluation guide:
(i) Target concept: Perfect competition as a market structure characterized by numerous small, price-taking firms, homogeneous products, and zero economic profit in long-run equilibrium; this chart illustrates the idea with only five firms (A–E) as a simplified schematic for 'no single dominant firm,' not a literal count of the many atomistic firms the full theory assumes.
Minimum mechanism: The pie chart must encode each firm's market share proportionally via sector angle; five approximately equal sectors serve as a pedagogical stand-in for 'no dominant firm, no hierarchy, no concentration'; with only five illustrative firms shown, a roughly 20% share is not literally 'negligible' in the strict atomistic sense, so the criterion to check visually is the absence of a disproportionately large sector, not literal insignificance of each firm's share.
(ii)Storyline: Frame 1–3: Chart fades in or appears fully formed (no partial construction). Frame 4–10: Static or gently stabilized view of completed chart; all five labeled sectors simultaneously visible, adjacent, and intact; labels remain spatially bound to sectors; no animation distracts from the balanced sizing; viewpoint remains frontal and fixed: no camera movement that breaks circular symmetry or sector adjacency.

Manual:
Experimental Procedure
1. Render a clean, centered pie chart with five contiguous, non-overlapping sectors.
2. Label each sector uniquely with uppercase letters A, B, C, D, E.
3. Assign each sector a distinct solid fill color and ensure no sector dominates in visual area.
Observation of Experimental Phenomena
A circular chart appears, divided into five clearly separated, similarly sized slices, each bearing one unique label (A–E) and a distinct color; no slice occupies majority area; all labels remain fixed and legible.
Summary of Experimental Principles
In a perfectly competitive industry, no single firm holds a dominant market share, and there are typically far more than five price-taking firms. This chart's five equally sized sectors are a simplified, illustrative proxy for 'no dominant firm' — with only five firms shown, each sector necessarily represents about 20% of the market, which should be read as a pedagogical stand-in rather than a literal depiction of the many small, atomistic firms the full theory of perfect competition assumes.

Prompt Grounding rubric:
level_1: No pie chart appears anywhere in the frame; none of the labels A, B, C, D, or E are shown; there is no circular chart structure of any kind.
level_2: A circular chart shape appears, but it is not divided into sectors; or one or more of the labels A-E appear but are not clearly tied to any wedge of the chart; or fewer than five distinguishable labeled wedges exist.
level_3: A pie chart with exactly five labeled sectors is shown; labels A, B, C, D, and E are all present and readable; each sector is visually set off from its neighbors by a border or color change; no company or label beyond A-E appears.
level_4: The pie chart has exactly five labeled sectors (A-E) that are clearly readable, each set off from its neighbors by a border or color change, with no other company or label appearing; the five sectors sit next to one another around a single shared center, forming a complete circle with no gaps; no label overlaps another, and each label sits clearly next to its own sector without floating unattached or being rotated illegibly.
level_5: The pie chart shows exactly five labeled sectors (A-E), each set off by a border or color change, forming one complete circle with no gaps and no overlapping labels; in addition, each sector has its own distinct fill color shared with no other sector, each label appears exactly once and is unmistakably paired to a single sector, no text is cut off, covered, or hard to read from rotation, and the chart sits centered and prominent in the frame with balanced margins.

Scientific and Causal Correctness rubric:
level_1: One sector clearly takes up more than half the pie (e.g., a single wedge dominating the chart), implying one firm controls the market; or a label like 'Dominant Firm' or 'Monopoly' appears; or the shares are shown as bars, a histogram, or a timeline instead of a pie chart.
level_2: The pie chart has five sectors, but two or more of them are exactly the same size and color, making them indistinguishable from each other; or labels A-E are attached to sectors in a way that looks arbitrary or inconsistent; or one sector is visibly much larger than the rest, which contradicts the intended 'no dominant firm' picture (even allowing that five equal slices are only a simplified stand-in for the true many-firm case).
level_3: All five sectors are visible and none dominates the chart (no single wedge looks noticeably larger than the others); all labels A-E are correctly attached to their own sector; the overall impression is of roughly equal shares, consistent with the simplified 'no dominant firm' convention used here (rather than the fully atomistic, many-firm version of perfect competition).
level_4: All five sectors are visible, correctly labeled A-E, and none dominates the chart, giving a rough impression of equal shares consistent with the simplified 'no dominant firm' convention used here; beyond that baseline, no two sectors show an extreme size difference (e.g., one visibly twice the width of another), and no label is swapped with the wrong sector (e.g., 'A' is not shown next to the largest wedge while 'E' sits next to the smallest).
level_5: All five sectors are visible and correctly labeled A-E with no extreme size difference between any two sectors and no mislabeled pairing; beyond that, all five sectors look essentially the same width to the eye, labels are placed in one consistent style throughout (all just outside with leader lines, or all centered inside), and nothing about the chart's size, color, or position suggests one firm ranks above or controls the others, matching the intended simplified illustration of 'no dominant firm' in this five-firm schematic.

Spatiotemporal Consistency rubric:
level_1: The pie chart vanishes and reappears in a different spot or orientation partway through the clip; sectors visibly tear, dissolve, or warp; labels jump to new positions between frames; the chart's center point drifts away or disappears mid-clip.
level_2: The chart stays on screen but sector boundaries flicker or vanish on and off; labels detach from their sectors and float on their own; the whole chart suddenly rotates or resizes with no smooth transition; the background behind the chart shifts in a way that looks inconsistent with the chart's own movement (or lack of it).
level_3: The pie chart stays fully visible and stable for the whole clip; all five sectors keep the same relative position and stay adjacent to each other; each label stays attached to its own sector the entire time; the chart never teleports, tears, or gets suddenly blocked from view.
level_4: The pie chart stays fully visible and stable for the whole clip, all five sectors keep the same relative position and adjacency, each label stays attached to its own sector, and the chart never teleports, tears, or gets suddenly blocked from view; beyond that, any motion present (such as a slow zoom or pan) is smooth and continuous, and it keeps the sectors' adjacency, the labels' attachment, and the circle's shape intact; the chart never looks stretched or squashed out of its circular shape during the motion.
level_5: The pie chart remains fully visible, stable, and unchanged in structure throughout: all five sectors keep the same relative position and adjacency, each label stays attached to its own sector, there is no teleporting, tearing, or sudden blocking of the view, and any camera motion stays smooth and continuous without stretching or squashing the circle out of shape; in addition, the chart's colors, proportions, and label text stay visually identical (no flicker, no color shift, no blurring in and out) from the first frame to the last, its scale and orientation on screen stay constant with no unexplained resizing or rotation, and nothing about the sectors or labels appears to shimmer, flash, or momentarily distort at any point in the clip.