Domain: Humanities and Social Sciences — Economics
Target concept: Diseconomies of scale: The average cost curve rises as output increases.

Video generation prompt: The figure shows a coordinate axis, with the horizontal axis representing output and the vertical axis representing average cost. A curve is plotted in the figure, illustrating how costs change with increasing output under conditions of diseconomies of scale.

Evaluation guide:
Target concept: Diseconomies of scale, defined mechanistically as the condition where proportional increases in all inputs yield *less than proportional* increases in output, causing average cost per unit to rise as scale expands. Minimum assumptions: (1) firm operates in long run (all inputs variable), (2) production technology exhibits diminishing returns to management/coordination beyond optimal scale, (3) input markets are imperfectly elastic (expansion bids up input prices). Expected phased storyline: (Phase 1) Empty coordinate plane appears with clearly labeled axes (Output x, Average Cost y); (Phase 2) A single smooth curve begins at low output/low cost and progresses strictly upward-rightward (no hesitation, reversal, or leveling), visually encoding causality: more output → higher average cost; (Phase 3) Final frame freezes with full curve visible and a concise on-screen text confirming "Diseconomies of scale: AC rises as output increases". Visibility constraints: Must be 2D planar, front-facing, orthographic projection, with no perspective distortion; all labels and curve must remain fully legible at native resolution; no occlusion, blur, or motion artifacts compromising verification of monotonic ascent.

Manual:
I. Basic Demonstration Information
Demonstration Title: Diseconomies of Scale — Rising Average Cost Curve Demonstration
Subject: Economics - Microeconomics - Production and Costs
Demonstration Purpose: To visually demonstrate that under diseconomies of scale, the long-run average cost (LRAC) curve rises as output increases — contradicting economies of scale — using a clean, labeled Cartesian graph; to reinforce the conceptual distinction between economies and diseconomies of scale via unambiguous visual morphology.

II. Demonstration Carrier/Equipment
Core Carrier: Static/dynamic 2D coordinate graph rendered in vector-style digital format
Auxiliary Equipment: None (pure graphical demonstration)

III. Demonstration Content Description
Layout: Centered Cartesian plane with horizontal axis labeled "Output" (left to right, 0 → Q_max) and vertical axis labeled "Average Cost" (bottom to top, 0 → AC_max). Origin (0,0) clearly marked. Gridlines optional but recommended for readability.
State Control: Graph remains static except for progressive curve revelation (left-to-right animation over 6–8 seconds). No human operator, no physical objects — pure information visualization.
Comparison Baseline: Curve must be strictly monotonic increasing (first derivative > 0 for all Q > Q_threshold); curvature may be linear or convex-upward, but never flat, decreasing, or U-shaped.

IV. Observation of Core Phenomena
Expected Phenomenon: A smooth, continuous curve enters frame from left and extends rightward, always ascending — never plateauing or descending — as it traverses increasing output values.
Expected Screen: Clean white or light-gray background; black or dark-blue axes and curve; bold, sans-serif axis labels; curve color distinct from axes (e.g., red or orange) for visual salience.
Visual Verification Features: (1) Horizontal axis unequivocally labeled "Output"; (2) Vertical axis unequivocally labeled "Average Cost"; (3) Curve slope is positive across its entire visible domain; (4) No secondary curves, annotations implying economies of scale, or misleading reference lines (e.g., no downward-sloping tangent).

V. Summary of Key Knowledge Points and Principles
Core Concept Definition: Diseconomies of scale occur when a firm’s expansion leads to higher per-unit production costs due to factors like coordination breakdown, bureaucratic inefficiency, or input market pressure — resulting in an upward-sloping long-run average cost curve.
Principle Visualization Logic: The rising curve is not merely descriptive — it is diagnostic: its strict monotonic ascent *is* the visual signature of diseconomies. Any deviation (flatness, decline, inflection) invalidates the demonstration.

VI. Demonstration Precautions
- Never overlay a U-shaped LRAC curve (which implies both economies *and* diseconomies); this demonstration isolates *only* the diseconomies region.
- Avoid labeling the curve "LRAC" without contextual clarification — instead, use direct functional label: "Average Cost vs. Output (Diseconomies of Scale)".
- Animation must proceed left-to-right *only* — no zooming, rotating, or panning that obscures axis integrity.
- Duration strictly capped at 10 seconds: 2s axis setup, 6s curve draw, 2s final freeze with label confirmation.

Prompt Grounding rubric:
level_1: No coordinate axes are visible anywhere in the frame, or axes appear but carry no text labels at all; no curve of any kind is drawn; the scene shows something unrelated to a cost-output graph (e.g., a bar chart, a 3D object, or a live-action scene).
level_2: Coordinate axes are present but mislabeled for this topic (e.g., the horizontal axis reads "Time" or "Price" instead of "Output", or the vertical axis reads "Total Cost" or "Marginal Cost" instead of "Average Cost"); or the axes are correctly labeled but no single continuous curve is drawn (only scattered dots or a broken, gapped line).
level_3: The horizontal axis is labeled "Output" and the vertical axis is labeled "Average Cost", and one continuous curve spans the plotted region, but setup quality is inconsistent: e.g., tick marks are missing from one axis, the origin point is not marked, the curve's line thickness visibly varies along its length, or the axis-label lettering is inconsistent in size or hard to read.
level_4: Both axes are correctly labeled ("Output" horizontal, "Average Cost" vertical) in clear, legible lettering, with tick marks present on both axes and the origin marked; a single continuous curve of even stroke width spans the visible output range without gaps; only minor cosmetic issues remain (e.g., faint gridlines, slightly uneven tick spacing) that do not hinder reading the graph.
level_5: Both axes are labeled ("Output" horizontal, "Average Cost" vertical) in bold, legible lettering, with evenly spaced tick marks and gridlines on both axes and the origin (0,0) clearly marked; a single continuous curve of uniform stroke width and color spans the full plotted output range with no gaps, no overlapping labels, and no rendering artifacts.

Scientific and Causal Correctness rubric:
level_1: The plotted curve is flat or trends downward across its full domain, so the graph shows average cost staying constant or falling as output rises. This depicts economies of scale or constant returns, the opposite of the diseconomies-of-scale relationship the prompt calls for.
level_2: The curve trends upward overall but reverses direction one or more times (e.g., it dips before climbing, or rises and then plateaus or falls), so there is no single output range across which cost consistently increases; the video does not unambiguously show that greater output causes greater average cost.
level_3: The curve rises consistently and without reversal across the entire plotted output range, correctly showing that average cost increases as output increases, but the video offers no further reinforcement of the concept, e.g., no confirming on-screen text and no reveal paced to match the output progression.
level_4: The curve rises consistently across the full output range AND is revealed progressively from left to right in step with increasing output (rather than appearing all at once or in a jumbled order), so the direction of the drawing motion itself reinforces that rising output drives rising cost.
level_5: The curve rises consistently across the full output range, is revealed progressively left to right in step with increasing output, AND the final frame displays on-screen text naming the concept and matching the curve's behavior (e.g., "Diseconomies of scale: average cost rises as output increases"), with no contradictory or extraneous text appearing anywhere in the video.

Spatiotemporal Consistency rubric:
level_1: The axes or curve abruptly relocate, vanish, or change orientation between frames (e.g., the vertical axis flips to the opposite side, or the plotted curve disappears and reappears with a different shape); the drawing order runs backward, with high-output segments of the curve appearing before low-output segments.
level_2: Axis labels or tick marks shift position or change size partway through the video; the curve-drawing motion stutters or visibly jumps ahead or back rather than advancing steadily; the flat 2D graph appears to tilt or take on a 3D perspective at some point in the sequence.
level_3: The axes stay fixed in place and the curve draws left to right in the correct low-to-high output order, but there is at least one noticeable hiccup: e.g., the drawing motion pauses and then resumes at a visibly different speed, or the curve's line thickness changes partway through.
level_4: The axes remain fixed in position and scale throughout the video; the curve is drawn continuously from left to right at a steady, even pace with consistent line thickness and color; axis labels and tick marks stay legible and in place for the entire video with no jumps or reversals in drawing order.
level_5: The axes remain fixed in position, scale, and orientation for the entire video; the curve draws with a steady, unbroken left-to-right motion at constant line thickness and color from the first frame to the last; axis setup, curve drawing, and the final freeze/label frame proceed strictly in the low-to-high output order throughout, with no visible position jump, reversal, or discontinuity anywhere in the sequence.