Rationale
Pizza as a reciprocal example is relatable and universal. "No matter how you slice it" is colloquial and friendly. The concept lands for anyone, including the target demographic. Loses a point because the pizza is a purple pie chart, not an actual pizza. The analogy says pizza; the visual says corporate quarterly earnings. A real pizza illustration would connect the demographic instantly.
Fix
Replace the pie chart with an illustrated pizza. Same slicing behavior, same math, but the visual is a pizza with toppings, cheese, crust. The code handles the slicing animation; the visual is a real asset.
Citation
design guide §6b "A programmatic trapezoid with a rectangle is not a coffee cup." A programmatic pie chart in purple gradients is not a pizza.
Rationale
Clean and approachable throughout. "Two numbers are reciprocals when you multiply them together and get exactly 1" is a perfect one-sentence definition. "No matter how you slice it" is warm. "Period and Frequency are the most important reciprocal pair in ultrasound. They will come up constantly." is honest and helpful without being condescending. Best tone in the trial set.
Fix
None needed.
Citation
design guide §1 "Conversational, supportive, never condescending."
Rationale
The concept tab is clean. The example tab makes it tangible. But the Visual tab jumps to a 1/x graph with axis labels "x" and "1/x," a slider labeled "Move along the curve," and the equation "0.3 x 3.5 = 1.0." A student who just learned what reciprocals are via pizza slices is now staring at an abstract mathematical curve with decimal multiplication. The leap from "pizza slices" to "asymptotic 1/x curve" is enormous and unscaffolded. The In Ultrasound tab then adds a second graph (Frequency vs Period) with no interactive. Two graphs on one card, one of which is entirely abstract math.
Fix
Bridge the gap between Example and Visual. After the pizza, show a simple table: "2 slices → each is 1/2. 4 slices → each is 1/4. 8 slices → each is 1/8." Then point out: "Notice the curve? More slices, smaller pieces, but it never reaches zero." THEN show the 1/x graph as the mathematical name for that shape. The graph should feel like a label for something already understood, not a new concept.
Citation
design guide §7 "Students should be able to interact at their own pace before seeing the full-speed version." The principle extends to abstraction: students should understand concretely before seeing the abstract representation.
Rationale
Concept → Example → Visual → In Ultrasound → Quiz. Correct flow. Bridge buttons present ("See an example →," "See the curve →," "Where does this show up in ultrasound? →"). Tab-to-tab progression is logical and well-signposted. Best structural flow in the trial set.
Fix
None needed.
Citation
design guide §2 Required flow: Cover → Concept → Example → Visual/Graph → In Ultrasound → Quiz → Self-Sort.
Rationale
The Concept tab introduces reciprocals as an idea: "Two numbers are reciprocals when you multiply them together and get exactly 1." Then immediately connects to the bigger principle: "Reciprocals are always inversely related." This is a concept, not a dictionary. Clean, two-sentence introduction of the big idea before any examples or details. Best concept tab in the trial set.
Fix
None needed.
Citation
acoustic-waves general "Sound exists as waves. That's a concept." This card follows that principle: reciprocals multiply to 1. That's the concept.
Rationale
The pizza analogy is conceptually perfect. "4 slices x 1/4 = 1 whole pizza" demonstrates reciprocals through something tangible. The slider changes the number of slices and the visual updates. The summary text ties it back: "More slices means each piece is smaller." All correct. But the visual is a code-drawn pie chart in random purple gradients, not a pizza. The text says pizza. The visual says data visualization. The random shade variation between slices has no pedagogical purpose and creates visual noise. And the interaction is controlled by a slider bar, Jenny's least preferred control type.
Fix
Replace the pie chart with an illustrated pizza asset (SVG with cheese, crust, toppings). The slicing animation stays code-driven; the visual becomes a real pizza. Replace the slider with tap-to-slice: the student taps/clicks to add a cut, watching slices get thinner. Or use +/- buttons for slice count. Direct manipulation over slider.
Citation
design guide §6b "Use <img> tags loading real SVG/PNG illustrations for scenario visuals. Use canvas/JS only for the interactive behavior layer." inverse-related feedback "I do not like having to drag the bar across the screen."
Rationale
Strongest In Ultrasound tab in the trial set by a wide margin. Leads with a graph (Frequency x Period = 1) that grounds the abstract concept in ultrasound terms. Then provides dropdown definitions for Frequency and Period with correct Definition/Example format and Jenny's exact anchor words ("How many," "How long one cycle"). The content is right. But: the graph is static (no interactive), the dropdowns are both expanded (should default collapsed), and a static graph is the primary experience on a tab that should prioritize manipulation.
Fix
Make the graph interactive: let the student drag a point on the curve and see Frequency and Period values update in real time. This is the seesaw/knob model that Jenny prefers. Default the Frequency and Period dropdowns to collapsed. The graph interaction becomes the teaching moment; the dropdowns become reference.
Citation
design guide §6 "Graphs are acceptable as supplementary visuals but should not be the primary interactive in Ultrasound sections. Prefer manipulation." inverse-related feedback Jenny's anchor word specifications for Frequency ("HOW MANY") and Period ("HOW LONG" and "ONE CYCLE") are correctly implemented here.
Rationale
"Reciprocals" and "inversely related" are colored purple consistently across the Concept, Example, and In Ultrasound tabs. "Frequency" and "Period" appear in purple on the In Ultrasound tab. Within this card, color usage is consistent. Deducting because Frequency and Period are major terms that will have their own dedicated cards; their colors here need to match whatever they are on those cards. Cannot verify cross-card consistency.
Fix
Verify Frequency and Period colors match the master term color list. If those terms have their own card colors, use those here instead of the reciprocals purple.
Citation
design guide §3 "Every key term gets a dedicated color assigned once and used everywhere that term appears across all cards."
Rationale
The In Ultrasound dropdowns follow the exact required format. Frequency: "Definition: How many wave cycles happen per second." / "Example: Higher frequency means more cycles packed into the same amount of time." Period: "Definition: How long one cycle takes to complete." / "Example: When frequency goes up, each cycle has less time, so period goes down." Term name colored and bold, definition and example labeled and visually separated. This is the reference implementation for definition format.
Fix
None needed. Use this as the template for all other cards' term definitions.
Citation
design guide §5 "All term definitions follow this format: Term Name (colored, bolded), Definition: One sentence. Anchor words bolded. Example: One sentence connecting to something familiar."
Rationale
"How many" bolded for Frequency. "How long one cycle" bolded for Period. "Exactly 1" bolded on the concept tab. "Inversely related" bolded. These are the testable recall phrases Jenny specified. Anchor word usage is the best in the trial set.
Fix
None needed.
Citation
inverse-related feedback "For Frequency I would BOLD the word(s) HOW MANY and for Period I would BOLD the word(s) HOW LONG and ONE CYCLE."
Rationale
Cannot evaluate from static screenshots. "Exactly 1" and "inversely related" should animate on first view.
Fix
Verify in live card.
Citation
design guide §4
Rationale
"When one gets bigger, the other gets smaller" on the concept tab. "When frequency goes up... period goes down" on In Ultrasound. These are directional relationships, but no warm/cool color coding is applied. Both directions are presented in the same purple. The inverse relationship is the entire point of this card, and the directional color system is not used to reinforce it.
Fix
Apply warm color to "bigger" / "goes up" and cool color to "smaller" / "goes down" in both the concept tab and the In Ultrasound definitions. The 1/x curve could also use warm-to-cool gradient along its length to show the directional shift.
Citation
design guide §4 "Warm color (red) for up/increase, cool color (blue) for down/decrease... applies anywhere directional language appears."
Rationale
Bold on "reciprocals," "exactly 1," "inversely related," "How many," "How long one cycle." All intentional, all testable anchors. No decorative bold. "Definition:" and "Example:" labels are bold, which is structural and appropriate. Clean.
Fix
None needed.
Citation
design guide §4 "Do not over-bold."
Rationale
No emdashes visible.
Fix
None needed.
Citation
design guide §3
Rationale
The pizza slider technically provides interaction: the student drags to change the number of slices. The 1/x graph slider lets the student move along the curve. But both are slider-controlled observation, not direct manipulation. The student doesn't slice the pizza; they move a slider and watch it slice. The student doesn't drag a point on the curve; they move a separate slider below it. Both interactives put a slider bar between the student and the concept. The In Ultrasound graph is entirely static.
Fix
Pizza: let the student tap/click the pizza to add cuts directly. Or drag a knife across it. 1/x graph: let the student drag the dot on the curve itself, not a separate slider. In Ultrasound graph: add a draggable point showing Frequency and Period values updating.
Citation
design guide §6 "Prefer manipulation over observation. Students should drag, turn, push, pull. Not just watch a dot on a graph." inverse-related feedback "I do not like having to drag the bar across the screen."
Rationale
Two slider bars. Two. On the same card. The pizza uses a slider for "Number of slices." The 1/x graph uses a slider for "Move along the curve." Slider bars are explicitly the least preferred control in Jenny's hierarchy. Using one is a demerit. Using two is a pattern.
Fix
Replace both sliders. Pizza: +/- buttons or direct tap-to-slice. Graph: draggable point on the curve itself. Neither interaction requires a slider bar. The slider is the lazy default; the alternatives are more tactile and align with the design guide.
Citation
design guide §6 "Seesaw/knob/draggable model > slider bar > static graph. Slider bars are the least preferred interactive." inverse-related feedback "I do not like having to drag the bar across the screen." Two sliders doubles the violation.
Rationale
No sound or sensory feedback. The pizza could produce a satisfying slice sound. The graph could produce a tone that rises/falls as you move along the curve (higher frequency = higher pitch, longer period = lower pitch). Especially on the In Ultrasound tab, where Frequency literally IS sound frequency, audio feedback would be a direct demonstration of the concept.
Fix
Add a slice sound to the pizza interaction. On the In Ultrasound graph, play a tone whose pitch matches the Frequency value as the student moves along the curve. This connects the abstract math to the physical reality the student will encounter in clinic.
Citation
design guide §6 "Sound and sensory feedback where possible." direct-related feedback "A sound get louder and quieter depending on which way they turn the knob."
Rationale
Both interactives earn their place conceptually. The pizza slider demonstrates reciprocals through concrete division. The 1/x graph slider shows the mathematical relationship. Both serve the concept. But the execution (sliders for both, no direct manipulation) undermines the justified purpose. And the In Ultrasound graph, which could be the most justified interactive on the card (showing Frequency x Period = 1 through direct manipulation), is static.
Fix
Keep the interactive concepts. Fix the control types (see E2). Add interactivity to the In Ultrasound graph.
Citation
rubric v2 §E4 "Interactive clearly improves understanding of the concept."
Rationale
The "pizza" is a code-drawn pie chart in random purple gradients. It is not a pizza. It is a circle divided into wedges with alternating shades of purple that serve no pedagogical purpose. The color variation between slices does not represent anything; it's arbitrary visual noise. The text says "pizza" and "slices"; the visual says "Q3 revenue breakdown." This is the most egregious programmer-art-as-finished-visual in the trial set because the text explicitly promises a recognizable real-world object and the visual delivers an abstract shape.
Fix
Replace with an illustrated pizza (SVG/PNG). Cheese, crust, toppings. The slicing lines can be code-drawn on top of the pizza asset. Each slice should look like a pizza slice, not a data wedge. The purple gradients should go entirely; if color variation is needed for slice differentiation, use subtle shading on the pizza itself (slightly darker where a slice separates), not random hue shifts.
Citation
design guide §6b "A programmatic trapezoid with a rectangle is not a coffee cup. A circle on a plank is not a seesaw." A purple pie chart is not a pizza. design guide §6b, flagged 3x "More realistic graphics."
Rationale
In Ultrasound tab has a graph with "Frequency" and "Period" labels. The graph correctly shows the reciprocal curve. But there's no clinical context: no transducer, no waveform, no scan image. The student doesn't see what Frequency and Period look like on an actual ultrasound machine. The graph is abstract math in an ultrasound costume.
Fix
Add context: show a simple waveform diagram alongside the graph where changing frequency visibly changes the number of cycles (more compressed waves = higher frequency = shorter period). Or show a transducer with labeled frequency output. Ground the math in what the student will see in clinic.
Citation
rubric v2 §F2 "Ultrasound-related visuals should resemble real practice."
Rationale
No placeholder frames. The purple pie chart is presented as the finished pizza visual. The graphs are presented as finished. No indication that real assets are needed or planned. The card treats its programmer art as complete.
Fix
Mark the pizza area with a dashed placeholder: "Illustration: pizza being sliced, showing reciprocal relationship between number of slices and slice size." Add a placeholder on the In Ultrasound tab for clinical imagery.
Citation
design guide §6b "When an illustration is not yet available, use a clearly marked dashed placeholder frame."
Rationale
Concept (text) → Example (concrete pizza) → Visual (abstract graph) → In Ultrasound (applied graph + definitions). The progression from concrete to abstract is correct. The pizza is the slow, tangible version; the 1/x graph is the fast, mathematical version. Good sequencing. Deducting because the gap between pizza and graph is too large (see A3).
Fix
Add a bridging step between Example and Visual (a simple table showing the numbers getting smaller as slices increase, before introducing the curve).
Citation
design guide §7 "Always show the slow, simple version of a visualization first."
Rationale
No auto-playing animations visible. The pizza and graph respond to slider input only. Cannot fully evaluate from static screenshots.
Fix
Verify in live card.
Citation
design guide §7
Rationale
Concept tab: two sentences. Excellent. Example tab: one sentence below the visual. Visual tab: one sentence above, one below. In Ultrasound: italicized intro sentence plus two dropdowns. Text economy is the best in the trial set. Deducting because the In Ultrasound dropdowns both appear expanded; they should default collapsed.
Fix
Default both In Ultrasound dropdowns to collapsed. The graph and intro sentence should be the primary view; definitions are opt-in reference.
Citation
design guide §8 "Collapse secondary explanations into dropdowns."
Rationale
The Example tab shows well (visual + short text). The Visual tab shows well (graph + short text). The Concept tab is tell-only (two sentences, no visual). The In Ultrasound tab leads with a graph (good) but has two expanded text dropdowns that dominate the bottom half. Mixed performance.
Fix
Concept tab: add a small visual hint of the reciprocal relationship (even just a simple animation of two bars, one going up as the other goes down). Collapse In Ultrasound dropdowns.
Citation
design guide §8 "Show, do not tell."
Rationale
The pizza container is reasonably sized. The graph containers fill their space. The Concept tab has moderate whitespace below the text and above the bridge button, but nothing extreme. Tighter than the comp-rarefaction slinky. Acceptable with minor improvements possible.
Fix
Reduce padding below concept text and above bridge button. Otherwise acceptable.
Citation
design guide §9 "Tighten whitespace."
Rationale
Each tab follows a clear flow: intro → visual/interactive → summary → bridge button. The In Ultrasound tab leads with the graph (visual anchor) then provides text reference (dropdowns). Concept tab is clean and minimal. Good hierarchy throughout, though the expanded dropdowns on In Ultrasound compete with the graph for attention.
Fix
Collapse dropdowns so the graph is the clear focal point.
Citation
design guide §9 "Clear visual hierarchy."
Rationale
The "Frequency" and "Period" dropdown headers on the In Ultrasound tab appear to use the brush title font. Same issue as all other cards: sub-section headers should use Tomarik Poster (all caps), not the brush font. Title "Reciprocals" correctly uses brush font.
Fix
Tomarik Brush for card title only. Tomarik Poster (all caps) for sub-headers.
Citation
design guide §11
Rationale
Visual tab graph: Y-axis labeled "1/x", X-axis labeled "x". These are mathematical labels, not meaningful ones. A beginner student doesn't know what "x" represents. The In Ultrasound graph: Y-axis labeled "Period", X-axis labeled "Frequency." These are real labels and much better. But no units on either axis (Period should show seconds or μs, Frequency should show Hz or MHz). The Visual tab graph fails; the In Ultrasound graph is better but incomplete.
Fix
Visual tab: relabel axes with something meaningful, or add context ("as one value increases → / the other decreases ↓"). In Ultrasound: add units to both axes. Both graphs should have gridlines or tick marks with actual values.
Citation
design guide §10 "Every axis is labeled with a unit. Never leave an axis as just 'x' or 'y'."
Rationale
Visual tab: the movable dot shows "0.3 x 3.5 = 1.0" and "0.1 x 10.3 = 1.0." Those annotations are useful. But the graph has gridlines with no values, no key relationship callouts, and no annotation explaining what the curve means visually (never touches zero). The In Ultrasound graph shows "Frequency x Period = 1" as a static label, which is good, but no specific value annotations, no clinical reference points (e.g., "typical diagnostic frequency: 3-10 MHz").
Fix
Add value annotations to gridlines. On the In Ultrasound graph, add reference markers for clinically relevant Frequency/Period pairs. Keep annotations minimal but meaningful.
Citation
design guide §10 "Annotations should teach, not decorate. One or two callouts per graph."