Domain: Humanities and Social Sciences — Economics
Target concept: Draw a bar chart comparing expenditures under a fiscal surplus.

Video generation prompt: The screen displays a coordinate system, with the horizontal axis representing funds and the vertical axis representing money. In the case of a fiscal surplus, a bar chart is created to represent income and expenditure.

Evaluation guide:
Target concept: Fiscal surplus as a quantitative condition (Income > Expenditure) made perceptible through comparative bar height in a Cartesian coordinate system. Minimum mechanistic assumptions: (1) Bars encode magnitude via height; (2) Same x-position implies same fund category; (3) Color coding is conventional (green = inflow, red = outflow); (4) Y-axis scaling is linear and consistent; (5) Surplus requires *systematic* height dominance, not just one instance. Phased storyline: [t=0s] Clean coordinate system appears with labeled axes; [t=0.5s] Paired bars begin growing upward from y=0 in sync; [t=1.8s] Bars stop, all green bars visibly taller than red counterparts; [t=2.0s] ‘Surplus’ annotation appears, referencing the height gap. Visibility constraints: Must be legible at 720p resolution; no occlusion; text size ≥24px; color contrast ≥4.5:1 (WCAG AA); perspective strictly orthographic, with no 3D foreshortening.

Manual:
I. Basic Demonstration Information
Demonstration Title: Bar Chart Visualization of Fiscal Surplus (Income vs. Expenditure)
Subject: Economics - Public Finance - Fiscal Policy
Demonstration Purpose: To visually demonstrate a fiscal surplus by generating a comparative bar chart where income consistently exceeds expenditure across budgetary funds; to reinforce that a surplus is defined by the quantitative relationship Income > Expenditure, made immediately perceptible through relative bar height; and to train recognition of axis semantics (x = funds/categories, y = monetary amount) in economic data visualization.

II. Demonstration Carrier/Equipment
Core Carrier: Digital charting interface (e.g., simplified matplotlib-style renderer) displaying a static-yet-animated bar chart.
Auxiliary Equipment: Clean white background; sans-serif font (Arial/Roboto); color palette: green (#28a745) for income bars, red (#dc3545) for expenditure bars; y-axis scale in realistic monetary units (e.g., billions USD); x-axis with ≥3 standard government fund categories.

III. Demonstration Content Description
Layout: Chart occupies center 80% of screen; coordinate system fully visible with orthogonal black axes; x-axis labeled ‘Funds’ below, y-axis labeled ‘Money (in billions USD)’ rotated 90° left; gridlines optional but non-distracting.
State Control: Bars animate upward from y=0 over 1.8 seconds, stopping simultaneously; income bars always terminate at a higher y-value than corresponding expenditure bars; surplus annotation appears at t=2.0s in top-right corner.
Comparison Baseline: Per-fund pair: identical x-position, equal bar width, 0.3-unit gap between income and expenditure bars; height ratio must satisfy Income ≥ 1.15 × Expenditure to ensure unambiguous surplus perception.

IV. Observation of Core Phenomena
Expected Screen: A clean Cartesian coordinate system. Horizontal axis lists 3+ fiscal funds (e.g., Education, Defense, Healthcare). Vertical axis shows ascending monetary values. For each fund, two vertical bars: left (green) = income, right (red) = expenditure. In every case, green bar visibly taller. A label reads ‘Fiscal Surplus Confirmed’ or displays numeric surplus (e.g., ‘+ $150B’).
Visual Verification Features: (1) Axes orthogonal and labeled per specification; (2) Bar colors strictly green/red with no hue shift; (3) Height dominance consistent across all fund categories; (4) No bar intersects x-axis origin — all start precisely at y=0; (5) Surplus annotation is spatially proximate and semantically linked (e.g., arrow pointing to height gap).

V. Summary of Key Knowledge Points and Principles
Core Concept Definition: A fiscal surplus occurs when total government revenue (income) exceeds total government spending (expenditure) over a given period; it is a stock-flow imbalance reflected in budgetary accounting.
Visualization Principle: Bar charts encode quantitative magnitude via length/height — making ordinal comparisons (e.g., income > expenditure) instantly recognizable. Axis labeling grounds abstraction: ‘Funds’ (x) denotes policy domains; ‘Money’ (y) denotes measurable economic value — together enabling structural interpretation of fiscal health.
Economic Significance: Sustained surplus signals fiscal discipline, enables debt reduction or reserve accumulation, and reflects macroeconomic stability — visualized here as systematic height dominance, not isolated numbers.

Prompt Grounding rubric:
level_1: No coordinate system is visible; no bars are present; the horizontal axis is not labeled for fund/budget categories and the vertical axis is not labeled for a monetary amount; there is no visual indication that this is an income/expenditure comparison (e.g., the scene instead shows a pie chart, a line graph, or unrelated shapes).
level_2: A rudimentary chart appears but fails basic setup: one axis is missing or mislabeled (e.g., the x-axis reads something unrelated to funds/categories, or the y-axis reads something unrelated to a money amount); axes are oriented incorrectly (e.g., bars run horizontally instead of vertically); or only one bar type (income or expenditure, not both) appears per category, with no consistent color or label distinguishing income from expenditure.
level_3: A coordinate system is visible with a labeled horizontal axis (e.g., 'Funds' or named budget categories) and a labeled vertical axis (e.g., 'Money' or a currency amount); at least two categories are shown, each with one income bar and one expenditure bar; income and expenditure bars are visually distinguishable by color or label, but spacing, bar width, or alignment to the axis ticks is inconsistent across categories.
level_4: All 3-point elements are present with 3 or more fund categories along the x-axis and a clearly labeled y-axis carrying a monetary unit (e.g., '$ millions' or '$ billions'); every category shows one income bar and one expenditure bar, consistently color-coded (one fixed color for income, a different fixed color for expenditure) and equal in width; bars are aligned to their category tick and start at the y=0 baseline; all text is legible; this holds regardless of which bar (income or expenditure) is taller in any given category.
level_5: All 4-point elements are present with clean, uncluttered rendering: bar pairs are evenly spaced across 3 or more categories, any gridlines do not obscure the bars, axis tick labels are evenly spaced and legible, and a surplus-related text annotation (of any content) is present near the chart without overlapping any bar or axis label; the chart's structural presentation is fully polished; this is scored independently of whether the income bar actually exceeds the expenditure bar in any or every category, since that comparison is judged elsewhere.

Scientific and Causal Correctness rubric:
level_1: The chart contradicts the fiscal-surplus premise: the expenditure bar is taller than the income bar in all or most categories, the axes are swapped (e.g., money plotted on the horizontal axis), or bar/axis labels are semantically wrong (e.g., a bar showing expenditure is labeled 'Revenue'); no visible link between the surplus condition and the bar heights.
level_2: Bar heights only weakly or inconsistently support a surplus: income exceeds expenditure in at most one category out of several; a surplus annotation is present but contradicts the bars (e.g., it appears while expenditure is taller); the y-axis has no consistent increasing scale; or income and expenditure bars are not visually distinguished by color, pattern, or label.
level_3: Income bars are taller than expenditure bars in at least two of the three (or more) categories shown, satisfying the basic surplus condition; income and expenditure use a consistent color or label distinction; the y-axis increases monotonically upward, though it may lack currency units or a realistic scale; the surplus is conveyed only through the visible height gap, without any accompanying numeric or text confirmation.
level_4: All 3-point elements are present with the income bar exceeding the expenditure bar in every displayed category (not just most); the color coding for income vs. expenditure is used consistently across all categories; the y-axis carries a realistic monetary scale with visible units (e.g., billions of dollars) and evenly spaced tick values; a supplementary annotation, inset, or footnote gives an explicit textual or numeric confirmation of the surplus, with any specific figures shown internally consistent with the bar heights actually rendered rather than a fixed canonical value; the chain from bar height to surplus conclusion is visually traceable.
level_5: All 4-point elements are present and the surplus reading needs no external explanation: bar heights are visibly proportional to the values they represent (a bar that looks roughly twice as tall as another reads as roughly twice the value, not an arbitrary or exaggerated gap); income (one consistent color) and expenditure (a different consistent color) bars are styled identically apart from hue; the surplus is reinforced in at least two independent, mutually consistent ways (e.g., per-category height dominance plus a totals annotation, or a highlighted gap between paired bars); a viewer unfamiliar with the underlying numbers could correctly conclude 'income exceeds expenditure' from the visual comparison alone.

Spatiotemporal Consistency rubric:
level_1: Chart elements flicker, jump position, or vanish partway through the sequence; the axes are redrawn inconsistently between frames (e.g., relabeled or repositioned); bars appear or disappear without any growth animation; axis or bar labels rotate or resize erratically; the coordinate origin visibly shifts during the sequence, bars appear detached and floating above the axis baseline, or an axis line bends into a non-straight, warped shape.
level_2: Noticeable but less severe instability: the axis lines wobble or change thickness across frames; bars grow with visibly jerky, non-smooth motion rather than steady growth; labels pop in or out abruptly instead of appearing gradually; the axes visibly lose their perpendicular alignment (skewing by more than roughly 10 degrees); or the surplus annotation appears before the bars have finished growing.
level_3: The axes stay in a fixed position and remain perpendicular to each other throughout; bars grow smoothly upward from the y=0 baseline; the axis labels, bars, and surplus annotation appear in a sensible order (axes first, then bars, then annotation) rather than all at once; minor timing inconsistencies are acceptable (e.g., one bar finishing slightly before another), but the overall sequence reads as smooth and logically ordered to the eye.
level_4: All 3-point elements are present with a high degree of visual smoothness: the axes appear fully formed at the start and stay fixed; all bars grow at a visually similar, steady rate and land precisely on their category tick positions when they stop; labels, bars, and the surplus annotation appear in a clear, consistent sequence; text stays sharp, centered, and a constant size throughout; there is no visible warping, stretching, or apparent shift in viewing angle across frames.
level_5: All 4-point elements are present with the smoothest presentation to the eye: the coordinate system is fully in place and motionless before any bar begins growing; every bar's growth looks continuous with no visible skips or pauses; the surplus annotation fades in only after all bars have stopped moving, appearing in a consistent, unobstructed location; the whole sequence looks free of stutter, popping, or abrupt jumps; bars stay perfectly vertical and equal in width no matter their horizontal position, consistent with a straight-on, non-perspective view of the chart.