Domain: Healthcare — Pathology
Target concept: Metaplasia (tracheal epithelial metaplasia)

Video generation prompt: A tracheal mucosal tissue specimen exposed to prolonged chemical stimulation is placed on the experimental table, and epithelial morphological changes are observed under the microscope.

Evaluation guide:
(i) Target concept: Tracheal epithelial metaplasia induced by chronic chemical exposure.
Minimum mechanism: Chemical irritant must be present and plausibly causative (e.g., tobacco smoke, SO₂, cadmium); epithelial transformation requires intact basal layer to permit replacement; squamous morphology must arise *de novo* at the surface without invasion or dysplasia.
(ii)Storyline: [Phase 1: Macro Setup] Specimen placed centrally on table beside labeled chemical container → [Phase 2: Transition] Camera moves smoothly toward microscope → [Phase 3: Micro Observation] Stable, focused view reveals uniform squamous epithelium replacing columnar layer, with intact basal zone and absent cilia/goblet cells → [Perspective constraint] Fixed viewpoint throughout; no cutaways to hands, labels, or external context beyond what is directly observable on table/microscope; [Visibility constraint] All diagnostic features (squamous morphology, basal layer, absence of cilia) must be simultaneously visible and unobscured in final microscope frame.

Manual:
Experimental Procedure
1. Place tracheal mucosal tissue specimen (pre-exposed to prolonged chemical stimulation) on clean experimental table.
2. Position specimen under light microscope and focus on epithelial surface.
Observation of Experimental Phenomena
Squamous epithelium replaces normal ciliated pseudostratified columnar epithelium; basal layer remains intact; no cilia or goblet cells visible in surface layer.
Summary of Experimental Principles
Prolonged chemical irritation induces tracheal epithelial metaplasia — reversible replacement of ciliated columnar epithelium by stratified squamous epithelium as a protective adaptation.

Prompt Grounding rubric:
level_1: No tracheal mucosal tissue specimen visible; no experimental table present; no microscope or microscopic view shown; no chemical stimulation context implied (e.g., no labeled reagent container, no exposure setup); demonstration objective completely absent.
level_2: Tracheal mucosal tissue specimen appears but is not placed on an experimental table; or microscope view is present but shows unrelated tissue (e.g., skin, lung parenchyma); chemical stimulation context missing (no container, no labeling, no exposure indication); sequence of placement → observation is absent or reversed.
level_3: Tracheal mucosal tissue specimen is placed on an experimental table; a microscope view is shown; the specimen is visibly present in the field of view; chemical stimulation context is minimally implied (e.g., a labeled chemical bottle adjacent to table, or text overlay “prolonged chemical exposure”); placement and observation occur in correct sequential order.
level_4: All elements from 3-score are present AND the microscope view exclusively shows tracheal mucosa (no other tissue types); the experimental table is uncluttered and clearly supports the specimen; chemical stimulation context is visually reinforced (e.g., droplet residue on specimen edge OR labeled container positioned adjacent with clear spatial relationship); placement occurs before observation, and no extraneous actions (e.g., handling with bare hands, rotating slide mid-sequence) interrupt the core sequence.
level_5: All elements from 4-score are present AND the specimen is centered on the table with consistent orientation across both macro (table) and micro (microscope) views; the microscope view shows only the mucosal surface (no slide frame, no air bubbles, no debris obscuring epithelium); chemical stimulation context is fully integrated (e.g., labeled container placed side-by-side with specimen on table AND its label is legible as a known metaplasia-inducing agent such as cigarette smoke extract or sulfur dioxide solution); placement → observation sequence is continuous, unbroken, and occupies the entire video duration without cuts or perspective shifts.

Scientific and Causal Correctness rubric:
level_1: Microscopic view shows normal ciliated pseudostratified columnar epithelium only, with no morphological change; or shows non-tracheal epithelium (e.g., squamous, transitional, or glandular); no evidence of metaplasia; no causal link between chemical exposure and epithelial change depicted.
level_2: Microscopic view shows epithelium with ambiguous morphology (e.g., mixed cell types without clear stratification or keratinization); or shows metaplastic features (e.g., squamous cells) but in incorrect location (e.g., submucosa instead of surface epithelium); chemical exposure is shown but no epithelial change appears; causal relationship absent or inverted.
level_3: Microscopic view shows epithelial layer with clear replacement of ciliated columnar cells by non-ciliated squamous cells; basal layer remains intact; this squamous morphology is present across ≥50% of visible epithelial surface; chemical exposure context is present; the change is visually attributable to the stimulus (i.e., no pre-existing pathology indicated).
level_4: All elements from 3-score are present AND the squamous epithelium shows uniform thickness and complete absence of cilia or goblet cells in the surface layer; no residual columnar cells intermixed in the superficial zone; underlying lamina propria is visible and unremarkable; chemical exposure context matches known metaplasia inducers (e.g., label reads “tobacco smoke condensate” or “SO₂ solution”); causal direction (exposure → squamous change) is unambiguously supported by visual continuity.
level_5: All elements from 4-score are present AND the squamous epithelium exhibits mature keratinization (visible eosinophilic cytoplasmic homogeneity and loss of nuclei in superficial layers); no mitotic figures in superficial zone; basal cell layer is sharply demarcated and uniformly cuboidal; no inflammatory infiltrate or ulceration; chemical exposure label matches clinical-pathological specificity (e.g., “chronic cadmium chloride exposure” for tracheal metaplasia models); every visual feature conforms precisely to WHO/IARC-defined histopathological criteria for squamous metaplasia.

Spatiotemporal Consistency rubric:
level_1: Specimen teleports between table and microscope view; sudden lighting shift or shadow discontinuity occurs mid-video; microscope view jumps between magnifications or rotates abruptly; specimen changes position/orientation without physical cause; structural break (e.g., torn epithelium appearing/disappearing frame-to-frame).
level_2: Macro view (table) and micro view (microscope) are shown in separate shots with inconsistent lighting, color balance, or scale; specimen appears in different orientations across views (e.g., longitudinal in table view, transverse in microscope view); time discontinuity evident (e.g., hand places specimen, then next frame shows fully zoomed microscope image with no transition).
level_3: Macro and micro views maintain consistent lighting temperature and brightness; specimen orientation is coherent across views (e.g., same anatomical axis visible); no teleportation or abrupt occlusion; motion is continuous (e.g., camera pans from table to eyepiece or slide advances smoothly); no structural breaks or warping artifacts.
level_4: All elements from 3-score are present AND lighting remains stable with no flicker or specular flare; specimen remains fixed in position during microscope view (no drifting, floating, or vibration); background elements (e.g., table texture, microscope body) retain consistent perspective and parallax; no inter-frame duplication or ghosting; motion (if any) is smooth and physically plausible (e.g., slide insertion follows natural hand trajectory).
level_5: All elements from 4-score are present AND macro-to-micro transition is achieved via a single continuous dolly/zoom that preserves spatial continuity (e.g., lens moves from tabletop down to microscope eyepiece, then seamlessly resolves into live microscopic field); specimen’s surface topography (e.g., mucosal folds) matches exactly between macro and micro scales; no temporal compression/expansion (e.g., no speed ramping); all shadows, highlights, and reflections obey consistent light source direction and intensity throughout.