Skill: write-like-james @ b0fa825 · the build: write-lesson, write-mcqs, write-video-script, review-lesson (two blind reads, a re-read and a polish pass), review-figures, review-accuracy @ b0fa825
Topic 7 "How sound and light travel and bounce" – your read (2 October 2026)
Skim first
The lessons in teaching order, each with its one rule sentence; then the intro script; then the question types. The review page follows.
The lessons and their rules
| Lesson | Atom | Rule sentence |
|---|---|---|
| L01 High in pitch or low in pitch? | ENE4-030 | How high or low a sound is. That is called its pitch. A whistle's sound is high in pitch. A big drum's sound is low in pitch. |
| L02 Faster vibration, higher pitch | ENE4-031 | The faster a thing vibrates. The higher in pitch its sound is. The slower it vibrates, the lower in pitch. |
| L03 Stronger vibration, louder sound | ENE4-032 | The more strongly a thing vibrates. The louder its sound is. A harder hit makes it louder, not higher in pitch. |
| L04 Draw the light's path to your eye | ENE4-050 | Light goes from the light source to the thing. It bounces off the thing to your eye. Draw two arrows: to the thing, then to the eye. |
| L05 Why the dark hides everything | ENE4-051 | In a completely dark room, no light reaches your eye. So you see nothing. To hear, a vibration must reach your ear. To see, light must reach your eye. |
The intro script (118 words, about 59 s)
Here's Miss Novak's class on a night walk in the woods, flashlights off. Colby's eyes are wide open, but he cannot see the trees, the path or his hands. Then an owl hoots, deep and slow, and a bat squeaks overhead. Colby hears both, from the dark. Nothing seemed to touch his ears, and nothing seemed to touch his eyes. So what reaches Colby when he hears, and what fails to reach him when he looks? To find out, we will look at what makes a sound high or low, loud or quiet, and what must reach your eye for you to see. Okay, so are you ready to find out what reaches your ears and your eyes?
The question types (from TYPES_G4T07.md)
- Type 1: High or low in pitch: four described sounds, pick the one high (or low) in pitch; or two sounds compared, four sentences, one true.
- Type 2: The term pitch: what pitch is (four quantities), or what changed when a note went higher; hard — type the word from its definition.
- Type 3: Predict pitch from the vibration's speed: a thing vibrates faster or more slowly; the four sister terms.
- Type 4: The reason for a pitch or loudness difference, or for a step of the light path: four reasons, one taught; hard — the rule run backwards.
- Type 5: Predict loudness from the vibration's strength: a thing vibrates more or less strongly; the four sister terms.
- Type 6: What changes and what stays: a harder hit, a louder note, a claim with the verdict fixed; which sentence is true.
- Type 7: Where the light's path starts, where an arrow goes, where the light bounces off; hard — type the part the light must reach.
- Type 8: Which drawn path: FOUR lettered paths on one scene (the taught path, the eye-beam, the path that misses the thing, the thing glowing with no arrow from the source); hard — judge a described wrong drawing by picking the right pair of arrows.
- Type 9: Why nothing is seen in the dark / what is seen: four outcomes or four reasons, the two named beliefs among them; judge a claim.
- Type 10: Select the set: the two arrows of the path, or the two things that must happen for a thing to be seen (multi-select), only where the answer is a set.
Five lessons: how high or low a sound is, is called its pitch; the faster a thing vibrates, the higher in pitch its sound is; the more strongly a thing vibrates, the louder its sound is; light travels from a light source to the thing, then bounces off the thing to your eye; in a completely dark room no light reaches your eye, so you see nothing. Every key agreed by two cold readers and by a third on the re-read, and the four items polished after that are in a fresh bundle. The figure review (every bounce leaves at the angle it arrived) and the guidance-and-accuracy review are applied. Pictures are placeholders until you answer.
The questions the author put to you (built as recommended)
1. Is "pitch" coined after the first pair of sounds, not last?
A sort by examples wants the quantity named: "high in pitch", never bare "high". Before the word is coined there is no name for it, so every case after the first pair can say "high in pitch" only if the coin comes early. Topic 1 coined "friction" last; this topic coins after the whistle and the drum.
Built: coined after the first pair; the rule restates the coin last.
Recommendation: after the first pair.
After the first pair / last
2. Is "quieter" the word for the sister of "louder", never "softer"?
The author first built "softer"; the reviewer answered with the record: Grade 3 Topic 11 says quiet and quieter fifteen times, and the atom says "louder or quieter". "Soft" also has a second everyday reading (squishy). About sixty strings changed; "softer" stays accepted on any typed answer.
Built: "quieter" and "quiet" throughout.
Recommendation: quieter.
Quieter / softer
The lessons
3. L01 High in pitch or low in pitch? – Miss Novak's music room: Colby's whistle is high, Colin's big drum is low, and the word for how high or low a sound is, is pitch; the same whistle blown more softly is quieter, and still high in pitch. page
4. L02 Faster vibration, higher pitch – Colin's ruler over the desk edge: the long part wobbles slowly and hums low in pitch; the short part is a blur and sounds higher. page
5. L03 Stronger vibration, louder sound – Cooper's drum with rice on its skin: a gentle tap, a quiet boom; a hard hit, a loud boom and the rice jumps high; the pitch is the same both times. page
6. L04 Draw the light's path to your eye – Colby reads a book under a lamp: the first arrow goes from the lamp to the book, the second from the book to his eye, because light bounces off a book just as it bounces off a mirror. page
7. L05 Why the dark hides everything – Cooper's basement bulb goes out: no light source, so no light lands on the box, none bounces off, none reaches his eye, and he sees nothing however long he waits. page
Applied without asking
The Moon is no longer called a light source; the night-time light comes from a streetlight or a porch light, as Grade 3 taught. Fourteen bank items that reused a lesson, practice or intro scene are re-scened, and the type sheet prints the scene grep that proves it. Three typed items whose question was not closed are four-option MCQs. L04 coins "light source" before it leans on the term. L05 says a bedroom at night is never completely dark, and a little light is what you see by. The pitch drawings no longer draw a slow vibration as a wide one, so speed is not read as loudness. Every light bounce now leaves at the angle it arrived, and every lamp stands on its table. The two drawn-path bank items carry four lettered paths, so no option is a sentence about eye beams. One bank item with two true sentences, one bank item that was another with the room renamed, and two practice items that repeated a quiz scene are rewritten in the polish pass. 54 bank items, 8 to 12 per atom; summary before practice; seven picture placeholders with briefs.
Also on the site
Topic intro and poll · summary and three questions · mixed practice · the PP100 bank · the type sheet
After you answer
Nothing on the page changes if you keep both; "last" or "softer" is a one-hour text pass. Either way the picture pass starts, and the seven-video batch goes on your word.
Build record (the structural decisions, the counts, v2 and v3)
Skill: course-build → write-lesson (L01 a two-class sort by examples with the loudness boundary case, coins "pitch" after the first pair; L02 a transformation taught worked on the ruler; L03 a transformation taught worked on the drum, confronting SND-06 by name; L04 a two-step drawing routine taught worked, Grade 3's reflection said to be the same thing; L05 the verdict / reason explanation, confronting LGT-01 and LGT-02 by name) → write-example-sequence, design-check-sequence, sentence-atomise, write-explanation, write-mcqs (attached questions, five quizzes, the mixed practice, the PP100 bank and its type sheet); write-video-script (the topic intro, five lesson scripts, the summary; the elementary micro-lesson anatomy); review-figures (author self-check on fifteen renders) @ b0fa825
Grade 4 Topic 7 — What reaches your ears and your eyes — build record (v1, 2 October 2026)
What this is, in plain words
Five short lessons, one per atom, that pair sound and sight under one question: what has to reach you for you to hear or see? A child first meets two quiet sounds in Miss Novak's music room — Colby's whistle and Colin's big drum — hears that one is high and one is low, and learns that how high or low a sound is, is called its pitch; the same whistle blown more softly is still high in pitch, so "high" is pinned to pitch and never to loud (L01). Next Colin's ruler over the desk edge: the long part wobbles slowly and hums low, the short part is a blur and sounds higher, so the faster a thing vibrates, the higher in pitch its sound is (L02). Then Cooper's drum with rice on its skin: a gentle tap, a soft boom; a hard hit, a loud boom, the rice jumping high, and the same low pitch both times — Colby's "the loud boom is higher" is answered in so many words (L03). Then Colby reads a book under a lamp and Miss Novak asks the class to draw the light's path: the first arrow from the lamp to the book, the second from the book to his eye, because light bounces off a book just as it bounces off a mirror (L04). Last, Cooper's basement bulb goes out: no light source, so no light lands on the box, none bounces off, none reaches his eye, and he sees nothing however long he waits; eyes do not send out light, and eyes "getting used to the dark" never see with no light at all (L05). The topic also carries the intro (a night walk with the flashlights off: the owl is heard, the trees are not seen), the summary, a mixed practice set with three Grade 3 retrievals, and a 54-item PP100 bank with its type sheet.
Not taught: how sound travels and how loudness falls with distance (Grade 3 Topic 11); the words frequency and amplitude (Topic 8, grades 6-8); why a shorter part vibrates faster (grades 6-8); refraction and absorption (Grade 3 Topic 14).
Structural decisions (in place of a blueprint)
James, 2 Oct 2026: no blueprint for Topics 4 on; the agent makes the structural decisions and records them here.
- Lesson order and titles (the architecture's atom order): L01 High in pitch or low in pitch? (ENE4-030) · L02 Faster vibration, higher pitch (ENE4-031) · L03 Stronger vibration, louder sound (ENE4-032) · L04 Draw the light's path to your eye (ENE4-050) · L05 Why the dark hides everything (ENE4-051, the capstone). Sound first because pitch is the only coined term and its two transformations share one scene kind; L04 then L05 because the dark-room reason is the path run with no source.
- Headache scenes: L01 Miss Novak's music lesson, a whistle and a big drum both played softly (so the difference is not loudness) · L02 Colin's ruler over the desk edge, long then short (the register's own example) · L03 Cooper's drum with rice, a gentle tap then a hard hit, and Colby's claim that the loud boom is higher in pitch · L04 Colby reading under a lamp, and Miss Novak asking the class to draw the path the light takes (a teacher would ask it) · L05 Cooper in a windowless basement when the only bulb goes out (a bulb burning out really happens).
- Where "pitch" is coined: after the first pair, not last. The term names the dimension the whole sort runs on, so the run ("A bicycle bell rings: its sound is high in pitch.") uses it, and the rule restates it last. Topic 1 coined "friction" last because the term named the class the run was building; here the plain words "high" and "low" are kept and the term labels the pair. Put to James below.
- Example sequences, written out: below.
- Check types: L01 (a) fluency · L02, L03, L04 (b) scaffolded → bare with the (c) claim items the atoms' misconceptions need · L05 (c) what / why / misconception / transfer, closed by a written why on a fresh case.
- Videos: L01–L04 video and article; L05 marked "could do without a video" (its scene is a dark room with nothing to show and its teaching is a chain of short sentences the article's figures carry), but scripted all the same so James can choose. L01's video is the one a child most needs, because an article cannot play a whistle and a drum.
- Sister words: "louder / softer" are the loudness pair (US classroom words), "higher in pitch / lower in pitch" the pitch pair, and the four are offered together wherever a change is predicted, so louder-means-higher is testable on every such item. "Gently / hard" name a hit, "soft / loud" a sound, so "soft" never doubles for the hit.
- The topic's one question is asked in the intro ("what reaches Colby when he hears, and what fails to reach him when he looks?") and answered twice: L05's last two lines and the summary's last beat ("To hear a thing, a vibration from it must reach your ear. To see a thing, light from it must reach your eye.").
Questions for James
- Coin "pitch" after the first pair (so the sort runs in "high in pitch / low in pitch"), or last, as Topic 1 coined friction? Context: the vault's High-and-low rule wants the quantity named, and before the coin there is no name for it; coining early lets every case after the first pair say "high in pitch". Recommendation: after the first pair. Built: after the first pair; the rule restates the coin last.
- "Softer" or "quieter" for the sister of "louder"? Context: the atom says "louder or quieter"; the standing brief for this topic named "louder / softer"; "soft" has a second everyday reading (squishy), guarded here by always pairing it with "sound" and by using "gently / hard" for the hit. Recommendation: softer, with quieter accepted on any typed item (
TOPIC["synonyms"]). Built: softer throughout.
Counts
5 lessons · scripts 147 / 149 / 139 / 146 / 149 spoken words (cap 150) · intro 119 words, 2 question marks · summary 153 words · article student text (idea, rule and subtitle lines) 186 / 168 / 203 / 226 / 258 words (grade4/check_g4_articles.py: WARN above 300; none) · 5 attached questions + the intro's poll + 3 summary questions · 55 quiz items (10 + 10 + 12 + 11 + 12; 1 written answer; 1 typed) · 13 practice items (11 MCQ, 1 typed, 1 written answer; 3 Grade 3 retrievals) · PP100 bank 54 items: 11 / 12 / 12 / 11 / 8 per atom; 18 easy · 23 medium · 13 hard; 47 four-option MCQs, 5 typed (one per atom), 2 multi-selects · 35 figures (28 svg by code, 2 photo placeholders, 5 cartoon placeholders) · checker 0 FAIL, 40 WARN (all S36, every word answered below) · check_g4_articles.py 0 FAIL · page builds (/tmp/g4t07_test.html: 5 lessons, 13 practice, 54 pp100, 35 figures) · names register run (below) · misconception checker: the three named beliefs appear only as "Some people say…" lines answered in the next sentence, as claim stems and as distractors.
What each lesson teaches
| Lesson | Atom | Lesson type | Example sequence (one frame) | Check type | Items |
|---|---|---|---|---|---|
| L01 High in pitch or low in pitch? | ENE4-030 | Two-class sort by examples; coins pitch after the first pair | Frame: "A X's sound is high in pitch." / "A Y's sound is low in pitch." Cases: H whistle · L big drum → coin → H bicycle bell → L cow's moo → H mouse's squeak → L tuba → the BOUNDARY (the same whistle blown more softly: quieter, still high in pitch; sorting sentence "How loud a sound is does not change its pitch.") → rule | (a) fluency: 8 high-or-low on fresh sounds, the last two the loudness boundary → the term by recognition → the term typed last | 10 |
| L02 Faster vibration, higher pitch | ENE4-031 | Transformation taught worked (the ruler), the band as the second case; Grade 3's fact recalled in one line | Worked: the long part vibrates slowly (you can see it wobble), low in pitch → the short part a blur, higher in pitch → the band loose, then pulled tighter → the table → rule, both halves | (b) after one ENE3-030 recall: 3 scaffold steps on a guitar string → 3 bare predictions → 1 why → a TRUE claim (Colin) → the reversed claim (Colby, bare no) | 10 |
| L03 Stronger vibration, louder sound | ENE4-032 | Transformation taught worked (the drum with rice); SND-06 confronted by name | Worked: a gentle tap, the skin vibrates only a little, soft → a hard hit, the skin vibrates strongly, loud → "No, Colby is not right. Both booms are low in pitch." → the band plucked gently and hard → the table → rule, with the drum sentence | (b) after one L02 recall: 2 scaffold steps on Colin's bell → does the pitch change (no) → 3 bare predictions → 2 sister-term sorts → a TRUE claim (Miss Novak) → the SND-06 claim (Colin, bare no) → 1 why | 12 |
| L04 Draw the light's path to your eye | ENE4-050 | Two-step drawing routine taught worked; Grade 3's rule recalled word for word; reflection's sameness said out loud | Worked: the lamp is the light source, so the first arrow goes from the lamp to the book → at the book the light bounces off, just as off a mirror (reflection; a book is not shiny, but light bounces off it all the same) → the second arrow to Colby's eye → the Sun and a tree → rule | (b) after two recalls (ENE3-017, ENE3-013): 3 scaffold steps on a mug under a flashlight → 2 drawn three-path items (J K L; M N P) → where the second arrow ends → 1 why → the LGT-07 claim (Colby, bare no) → a TRUE claim (Colin) | 11 |
| L05 Why the dark hides everything | ENE4-051 | Verdict / reason explanation; LGT-01 and LGT-02 confronted by name; the capstone | With the bulb on, the path → with the bulb out, no light source → no light on the box → none bounces off → none reaches his eye → he sees nothing → "Some people say your eyes send out light…" answered → "…get used to the dark" answered, the little light at night traced to a source → the phone's flashlight restores the path → rule → the topic's two answers | (c) after one L04 recall: what (the cave) → why → LGT-01 claim (Colin, no) → LGT-02 claim (Colin, no) → a TRUE claim (Colby) → transfer (a flashlight in the cave) and its why → the night-time source → what must reach your ear / your eye → the why as a written answer (Colin's closet) | 12 |
Design-check-sequence records
`
Skill: design-check-sequence @ b0fa825
Part: L01 (ENE4-030)
Type: (a) one-step categorisation — is this sound high in pitch or low in pitch? (two labels)
Plan: bird's chirp (h) → thunder (l) → truck's engine (l) → squeaky hinge (h) → kitten's mew (h) → bullfrog's croak (l) → Cooper's loud deep hum (l, the loudness boundary) → a triangle tapped so gently you can barely hear it (h, the other side) → term by recognition (3 opt, 1) → term typed, last. Two-option string h l l h h l l h.
Belongs in practice/test instead: four-sound picks (PP-1, 2, 4); comparisons as true sentences (PP-3, 6); pitch × loudness pairs (PP-7, 21).
`
`
Skill: design-check-sequence @ b0fa825
Part: L02 (ENE4-031)
Type: (b) multi-step routine — is it vibrating faster or slower → so is its sound higher or lower in pitch?
Plan: recall ENE3-030 (a bowed cello string is vibrating; 3 opt, 0) → scaffolded on Colby's guitar string: the shorter part vibrates faster (0) → so higher in pitch (0) → the whole string again, slower, lower (1) → bare: the long xylophone bar (1), mosquito / bumblebee whose is lower (1), Cooper's tightened drum skin (0) → why: the big church bell (3 opt, 0) → TRUE claim, Colin (yes) → reversed claim, Colby (no). Two-option string 0 0 1 1 1 0 0 1 (first option = faster / higher / the first-named / yes); three-option 0 0.
Belongs in practice/test instead: four-option sister-term items (PP-9, 10, 24); the rule run backwards (PP-25, 44); which change raises pitch (PP-26).
`
`
Skill: design-check-sequence @ b0fa825
Part: L03 (ENE4-032)
Type: (b) multi-step routine — is it vibrating more or less strongly → so is its sound louder or softer? — with the (c) claim the atom's cross note names (loudness isolated from pitch).
Plan: recall L02 (the short pipe's sound is higher; 2 opt, 0) → scaffolded on Colin's bell: which hit makes it vibrate more strongly (1) → which makes the louder sound (1) → is it also higher in pitch (no, 1) → bare: Colin's gentle strum, softer (1); the cricket, louder (0); the gently plucked band, soft (0) → sister-term sorts: a bar hit harder (3 opt, 1), a ruler's shorter part (3 opt, 2) → TRUE claim, Miss Novak (yes, 0) → SND-06 claim, Colin (no, 1) → why: the hard-plucked band (3 opt, 1). Two-option string 0 1 1 1 1 0 0 0 1; three-option 1 2 1.
Belongs in practice/test instead: four-option sister-term items (PP-13, 14, 27, 32); what stays the same (PP-29); two changes in one scene (PP-46); the four hits (PP-47).
`
`
Skill: design-check-sequence @ b0fa825
Part: L04 (ENE4-050)
Type: (b) multi-step routine — where does the light start → where does the first arrow go → where does the second arrow go (the drawing picked and judged, since the platform has no drawing tool).
Plan: recall ENE3-017 (when do you see a thing; 3 opt, 0) → recall ENE3-013 (light bouncing off a wall is reflection; 3 opt, 0) → scaffolded on Colin's mug under a flashlight: the light starts at the flashlight (3 opt, 1) → the first arrow goes to the mug (0) → the second arrow goes to Colin's eye (1) → bare: three lettered paths, lamp / cup / eye (J K L; K, 1) → streetlight / dog / eye (M N P; P, 2) → where the second arrow ends, a ball under a lamp (3 opt, 1) → why the second arrow starts at the cup (3 opt, 2) → LGT-07 claim, Colby (no, 1) → TRUE claim, Colin (yes, 0). Three-option keys 0 0 1 1 2 1 2; two-option string 0 1 1 0.
Belongs in practice/test instead: the four-option path items with the eye-beam belief as the fourth option (PP-34, 35); a wrong drawing judged (PP-49); the set item (PP-50); the typed end of the path (PP-48).
`
`
Skill: design-check-sequence @ b0fa825
Part: L05 (ENE4-051)
Type: (c) concept understanding — why nothing can be seen in a completely dark room; the catalogue names LGT-01 and LGT-02.
Plan: recall L04 (where the second arrow ends, a flower in sunshine; 3 opt, 1) → the what: Colby in a cave with no light (3 opt, 2) → the why (reasons, 3 opt, 0) → LGT-01 claim, Colin (no) → LGT-02 claim, Colin (no) → TRUE claim, Colby (yes) → transfer: a flashlight in the cave (3 opt, 2) → its why (3 opt, 0) → the night-time source (3 opt, 1) → what must reach your ear (3 opt, 1) → what must reach your eye (3 opt, 0) → the why as a written answer on a fresh case (Colin's closet; the fresh-case form, read against the article's basement, cave, night window and phone cases). Three-option keys 1 2 0 2 0 1 1 0; two-option string n n y.
Belongs in practice/test instead: reasons as four options (PP-39, 52, 54); the typed verdict (PP-51); the set item (PP-53); which change lets him see (PP-41).
`
The key strings
- Attached questions in video order (L01, L02, L03, L04, L05, summary 1–3): 0 1 1 2 0 1 0 2 — position 0 holds 3 of 8, position 1 holds 3 of 8, position 2 holds 2 of 8.
- Lesson quizzes, two-option items: L01
h l l h h l l h· L020 0 1 1 1 0 0 1· L030 1 1 1 1 0 0 0 1· L040 1 1 0· L05n n y— no four in a row alternate; no position above 60 % within a lesson. - Three-option items: L01
1; L020 0; L031 2 1; L040 0 1 1 2 1 2; L051 2 0 2 0 1 1 0; practice two-option0 1 1 1 0(PR-1, 2, 4, 6, 7), three-option1 1 0 1 0 2(PR-3, 5, 8, 9, 10, 12). - PP100, 47 MCQs in bank order:
C A B D B C D B A D B B A D A A A C B D C A B D A C D A C B B D C C A D C B A B D A C D B D A— A 13 · B 12 · C 10 · D 12 (max 28 %; S7's 35 % line clear).
The example sequences, written out
L01 (one frame from the coin on; the rule restates the coin last):
- Colby's whistle, blown softly → its sound is high, like a bird's tweet. Colin's big drum, tapped softly → its sound is low, like a dog's growl. → "How high or low a sound is, is called its pitch." → the whistle's sound is high in pitch; the drum's sound is low in pitch.
- A bicycle bell rings, ting → its sound is high in pitch.
- A cow moos → its sound is low in pitch.
- A mouse squeaks → its sound is high in pitch.
- A tuba plays → its sound is low in pitch.
- The same whistle, blown even more softly → quieter, but still high in pitch. "How loud a sound is does not change its pitch." (the boundary case and its sorting sentence)
- Rule: How high or low a sound is, is called its pitch. A whistle's sound is high in pitch, and a big drum's sound is low in pitch.
L02 (the transformation, worked): "Every sound is made by something vibrating." (Grade 3, one line) → the long part of the ruler vibrates slowly, you can see it wobble → its sound is low in pitch → the short part vibrates so fast that it is a blur → its sound is higher in pitch → the rubber band loose vibrates slowly, low in pitch → pulled tighter, it vibrates faster → its sound is higher in pitch → the table → Rule: The faster a thing vibrates, the higher in pitch its sound is. The slower a thing vibrates, the lower in pitch its sound is.
L03 (the transformation, worked, and the claim answered): a gentle tap → the skin vibrates only a little → a soft sound · a hard hit → the skin vibrates strongly, the rice jumps high → a loud sound → "No, Colby is not right. Both booms are low in pitch. The hard hit made the boom louder, not higher in pitch. How strongly a thing vibrates changes how loud its sound is, not its pitch." → the band plucked gently (only a little, soft) and hard (strongly, loud), the pitch the same → Rule: The more strongly a thing vibrates, the louder its sound is. Hitting a drum harder makes its sound louder, not higher in pitch.
L04 (the routine, worked): "You see something only when light from it reaches your eye." (Grade 3, word for word) → the book does not make light → the lamp is the light source, so the first arrow goes from the lamp to the book → at the book the light bounces off, just as it bounces off a mirror → "Light bounces off the things it hits, and this is called reflection." → a book is not shiny, but light bounces off it all the same → so the second arrow goes from the book to Colby's eye → he sees the book → the Sun and a tree: the same two arrows → Rule: Light travels from a light source to the thing, then bounces off the thing to your eye.
L05 (the chain, and the two beliefs answered): with the bulb on: bulb → box → eye · with the bulb out: no light source → no light lands on the box, so none bounces off it → none reaches Cooper's eye, so he sees nothing · "Some people say your eyes send out light to see things. But eyes do not send out light. If they did, Cooper would see the box in the dark." · "Some people say your eyes get used to the dark and then see a little. But where there is no light at all, you see nothing, however long you wait. When you see a little at night, light is coming from somewhere, like a streetlight or the Moon." · the phone's flashlight: phone → box → eye, he sees the box · Rule: In a completely dark room, no light reaches your eye from anything, so you see nothing. To hear a thing, a vibration from it must reach your ear. To see a thing, light from it must reach your eye.
The misconception rows (the catalogue, grades 3-5) and what was done
| Row | Belief | Done |
|---|---|---|
| SND-06 | hit it harder and the note goes higher; loud means high | L01's boundary case (the same whistle blown more softly is still high in pitch) and sorting sentence; L03's headache claim (Colby) answered in so many words in the article and the script; L03-q4 (does the pitch change: no), L03-q11 (Colin, bare no), PR-6 (Cooper, bare no); the sister-term option set on every prediction item; PP-20, 21, 28, 29, 31, 46 |
| LGT-01 | I see because my eyes look at things; the eye drawn as the start of the arrow | L05 "Eyes do not send out light" part, stated as what some people say and answered in the next sentence; the one wrong drawing in the topic (eye_beam_wrong, an arrow from the eye, crossed out, chip THIS DRAWING IS WRONG); L05-q4 (Colin, bare no); the eye-beam path as a lettered distractor on every three-path figure; the fourth option "no path, because the eye sends out light" on PP-34, 35; distractors on L04-q3, q6, q7, q9, PP-52, 53 |
| LGT-02 | in the dark your eyes get used to it and then you see a bit | L05 article "however long he waits" and the "Some people say your eyes get used to the dark…" lines answered in the next sentence, the little light at night traced to a streetlight or the Moon; L05-q5 (Colin, bare no), L05-q6 (Colby, TRUE claim), L05-q9; PP-40, 41, 52, 53, 54 |
| LGT-07 | only mirrors and shiny things reflect light | L04 "A book is not shiny, but light bounces off it all the same." and the mirror_book_same figure; L04-q10 (Colby, bare no); PP-38 |
| SND-01 | the sound comes from hitting it; the drum isn't doing anything | avoided by wording: every sound sentence names the vibrating thing ("the skin vibrates", "the string vibrates"); Grade 3's fact recalled in L02's first teaching line and in L02-q1, PR-3 |
| SND-07 | the sound dies away because it runs out | avoided by wording: no "dies away", "fades", "runs out" anywhere |
| ENE-06 | light, sound and electricity are kinds of energy | avoided: the words "energy" and "form" do not appear in the topic's student text |
python3 build_tools_physics_misconceptions.py grade4/topic07_build/content/G4T07.py: the two high-weight phrases ("eyes send out light", "eyes get used to the dark") each occur once, in L05's "Some people say…" lines, answered in the next sentence; "louder, not higher" (SND-06, low) is the correction phrase itself, nine times, as designed; 8 claim stems and 5 distractors carry a row's phrase, as designed.
The 2 October rules, applied
| Rule (vault note) | Where it bites here |
|---|---|
| Every sentence has a subject and a verb (S38) | 0 fragments; "Why?" asks became "Why is the big bell's sound lower in pitch?" / "Why can Colby see nothing in the cave?" |
| Connectives carry cause; a turn opens with But | "The long part vibrates slowly: you can see it wobble."; "But eyes do not send out light."; every fb and why joins cause and effect with "so" |
| The positive word | "soft", "quieter", "sees nothing", "stays the same" — never "not loud", "does not change" where a positive word exists |
| Compound names whole | "light source", "drum skin", "rubber band", "kitchen table", "bicycle bell", "smoke alarm" |
| No second everyday reading | "a tiny bat squeaks overhead" (not "high above him"); "gently / hard" for the hit so "soft" means only the sound; "the bulb goes out" (not "the light dies") |
| High and low always name their quantity | "high in pitch / low in pitch" from the coin on; before the coin "high, like a bird's tweet" with the comparison named |
| Units as words; numerals on chips (S29) | the one number in student text is "ten minutes" (PP-40); chips carry no numbers; S29 count 0 |
| Biggest / smallest for size only (S39) | 0 hits; "highest in pitch", "the most" |
| Light, sound and electricity carry energy, never forms | the words "energy" and "form" do not appear in the topic's student text (the atoms teach pitch, loudness and the path, not the transfer) |
| Light changes direction; reflection is one direction; equal angles | every bounce is drawn with Topic 14's bounce_to (angle in = angle out); no fan; "changes direction" and "bends" do not appear |
| A non-example is a near miss | L01 has no non-example (the sort has two classes); the boundary case is the same whistle blown more softly; the three-path figures' wrong paths are the two drawings a child makes |
| Coin as "is called", explain then label | "How high or low a sound is, is called its pitch." after the whistle and the drum have been heard as high and low |
| A coined term is used from then on; one-line recap on first reuse | L02's headache says "higher in pitch" from its first line; "reflection" (Grade 3's) gets its recap "Light bounces off the things it hits, and this is called reflection." before it is used; "vibrating" is recalled in one line |
| After a term is coined the scaffold noun is retired | "high" and "low" alone never describe a sound after the coin except inside "high in pitch / low in pitch" and the plain similes "like a bird's tweet" |
| Hard means more of the skill | every hard bank item has its "hard because" line (type sheet); no riddle, no stranger scene |
| Physics lessons confront the age's misconceptions by name | the table above: SND-06 in L03, LGT-01 and LGT-02 in L05, LGT-07 in L04 |
| Lesson titles name the skill in student terms | High in pitch or low in pitch? · Faster vibration, higher pitch · Stronger vibration, louder sound · Draw the light's path to your eye · Why the dark hides everything |
| Students never see the word strand (S37) | 0 hits |
| Summary opens "Here's everything we found out about …", rules not examples | the opener, then the ten lexicon sentences with lead-ins (First / Next / Then / Then / And last), no example re-told, 153 words |
| Intro ≤ 120 words, ≤ 3 question marks, coins nothing, one scene, map line, ready line + poll | 119 words, 2 question marks, no "is called", one scene (the night walk), "To find out, we will look at …", "Okay, so are you ready to find out what reaches your ears and your eyes?" |
| The intro's scene could really happen; no invented notice | a class night walk with the flashlights off; the owl and the bat are heard, the trees are not seen |
| A headache scene could really happen there | a music lesson; a ruler flicked at a desk; rice on a drum; a teacher asking the class to draw; a basement bulb burning out |
| An attached question stands alone (S27) | every attached stem names its own scene (a tiny bell; a pressed guitar string; a plucked string; a red ball in sunshine; a shut closet; a xylophone; a bell rung hard; a windowless room) |
| Recognition before recall (S33 / S34) | "pitch" offered in L01-q9 and PR-12 before it is typed in L01-q10, PR-13, PP-42 |
| A quiz climbs recognise → apply → produce (S32) | the typed item sits last in L01 and the practice set; the written answer last in L05 |
| A stem never names its key (S13) | the one S13 warning (mosquito / bumblebee) cleared by naming the animals without the possessive |
| Fresh instances (S10) | 0 S10 warnings; no lesson's quiz names that lesson's headache characters (L02 uses Cooper and Colby, L03 Colin and Miss Novak, L05 Colin and Colby) |
| An option never bundles a verdict with its reason | every claim item in the quizzes is bare yes / no with the correction in the why; the bank fixes the verdict in the stem and offers reasons (PP-21, 31, 54) |
| The what and the why are two items | L05-q2 (what he sees) and L05-q3 (why); L05-q7 (what happens) and L05-q8 (why); the written why on a fresh case |
| Lesson text states the fact, never the topic that taught it | "Every sound is made by something vibrating." / "You see something only when light from it reaches your eye." — no "in Grade 3 you saw" |
| Figures: three kinds (James, 2 Oct) | 28 svg diagrams, tables and rule cards; 2 photo placeholders (a whistle, a big drum); 5 cartoon placeholders (the music room, Colin's ruler, Cooper's drum, Colby reading, the basement); IMAGE_KINDS and IMAGE_BRIEFS complete; no person, hand or arm drawn as a glyph except the oblong arm that holds the phone in basement_phone (the Grade 3 convention) |
| One depiction per thing, imported never redrawn | the ruler, the motion lines, the drum, the drumstick, the rice, the rubber band on its box from Grade 3 Topic 11; the gold light line, the lamp, the Sun, the flashlight, the candle, the streetlight, the book, the mug, the vase, the dog, the ball, the eye, the verdict line from Topic 13; the flat mirror, the bounce geometry and the cat from Topic 14 |
| A verdict mark names its question | every chip sits under its question: "High in pitch or low in pitch?", "How fast does it vibrate?", "How strongly does the skin vibrate?", "Where does the light start?", "What does the light do at the book?", "Does light from the box reach his eye?" |
| A headache figure is the teaching figure with the answer's layer off | path_headache is path_step2 without the arrows and chips; drum_two_headache is drum_two_answer without the motion marks and chips; ruler_long_headache carries the vibration (Grade 3's layer) but no speed chip |
| A wrong drawing is called wrong | eye_beam_wrong: the one line in the topic that leaves an eye, with a red cross and the chip THIS DRAWING IS WRONG |
| Motion in an article is animated where the motion is the point | ruler_anim: the long part swings slowly (1.4 s a cycle), the short part fast (0.25 s); the one animation in the topic; never on an item |
| A character's name belongs to one topic | Miss Novak, Colby, Colin, Cooper only (grade4/NAMES_POOL.md, Topic 7 row); no other name appears in any student string |
| US spelling (S14) | "color", "meters" (none needed); 0 warnings |
Checker: 0 FAIL, 40 WARN (python3 build_tools_check_topic.py grade4/topic07_build/content/G4T07.py)
All 40 are S36 readability words. Each answered:
- Kept as everyday Grade 4 words or the names of common instruments and animals (fine): gently, growl, chirp / chirps, pluck / plucks / plucked / plucking, tweet, guitar, ting, tuba, flicks, hoot / hoots, flute, piccolo, xylophone, blur, mosquito, cricket, bass, reed, wasp, wobble, cello, beep / beeps, hinge, zipped, chime, tambourine, teddy, cymbal, traffic (light), whine, strums, harmonica, shelves, trumpet.
- Swapped before this record: "fetch / fetching" → "get / getting"; "hedge" → "bush"; "prongs" → "arms"; "unseen" → "cannot be seen"; "shininess" → "need not be shiny"; "scene" (in two why lines) → "the question".
- Clean: S1–S35, S37, S38, S39; S30 typed 7, 0 fail, 0 warn; S29 0; S31 (bank difficulty by atom order and coverage) clean; S7 clean in every lesson and the bank; S11 clean (54 items, four options per MCQ, typed accept lists, non-decreasing d, every atom covered); S22 clean after three stems were rewritten to one negative word; S23 clean after four two-sentence rewrites.
python3 grade4/check_g4_articles.py grade4/topic07_build/content/G4T07.py → 0 FAIL (articles 186–258 words, under the 300 WARN line; scripts 139–149; intro 119; summary 153, opener correct).
Figures (35; author's review-figures self-check on fifteen renders at 1000 px)
Depiction register in figures.py's docstring. Renders opened: path_step2, drum_two_answer (fixed twice: the drumstick ran into the SOFT chip and the panel labels into the question; the stick now comes from the upper right, the chips sit higher, the motion strokes on the skin are wider), q_paths_cup (fixed: the eye-beam path had been drawn as the taught path reversed and lay on top of it — it is now ONE arrow from the eye to the thing's side, at its own angle, and the register says so), q_paths_dog, pp_paths_cat, ruler_anim, ruler_long_headache, basement_no_light, pitch_table, eye_beam_wrong (fixed: the chip and note sat over the hanging bulb; moved to the left), path_tree, mirror_book_same, band_tight, rule_louder, basement_phone. The table drawer measures every cell against its column (CHAR = 7.2 px a glyph at 13 px) and asserts the fit; both tables render inside their frames. Placeholders: the five cartoons and two photos carry notes and alt text that name no item's answer; the picture stage (David's pack) owes 7 pictures; their briefs are in IMAGE_BRIEFS. Per the 2 Oct sequencing rule, this topic has two Questions for James, so its picture pass waits for his sign-off.
Sentence-atomise self-check (summary per lesson; every idea line one sentence, S1 / S38 clean)
| Lesson | Ideas | One idea per sentence | Cause → effect | Named actor | Verb carries | Plain word before term | ≤ 8 lines per run | Fixes applied |
|---|---|---|---|---|---|---|---|---|
| L01 | 15 | yes | yes (the sound, then its class; the loudness change, then the unchanged verdict) | Colby, Colin, the whistle, the drum, the bell, the cow | blows, taps, rings, moos, squeaks, plays | high / low → pitch | yes (four subtitles) | "softly" kept for the blow, "quiet / quieter" for the sound, so no word doubles |
| L02 | 15 | yes | yes (slow wobble → low; fast blur → higher; tighter → faster → higher) | Colin, the ruler's long part and short part, the band | holds, flicks, hums, slides, vibrates, wobbles, plucks, pulls | vibrating recalled before "vibrates faster" | yes (four subtitles, one animation) | "He pulls the band tighter, and it vibrates faster, so its sound is higher" split into two lines (two causal links) |
| L03 | 18 | yes | yes (the hit → how strongly the skin vibrates → how loud) | Cooper, Colby, the skin, the rice, the band | taps, hits, vibrates, hops, jumps, plucks | gently / hard before soft / loud | yes (five subtitles) | "softly" → "gently" for every hit; "Is he right?" answered verdict-first ("No, Colby is not right.") |
| L04 | 15 | yes | yes (the source → the first arrow; the bounce → the second arrow; reaches the eye → he sees) | Colby, Cooper, Miss Novak, the lamp, the book, the Sun, the tree | reads, asks, bounces off, goes, reaches, sees | "bounces off" before "reflection" | yes (five subtitles, seven figures) | "Is Colin's drawing right?" cut from the headache so the article answers only the question it asks; "The book does not make light" added as the obvious step |
| L05 | 19 | yes | yes (no source → no light on the box → none bounces off → none reaches his eye → nothing seen) | Cooper, the bulb, the box, the phone | goes out, lands, bounces off, reaches, sees | none coined | yes (five subtitles, six figures) | "fetch" → "get"; "Some people say…" lines each answered in the next sentence with "But…" |
Names register (python3 build_tools_names.py Novak Colby Colin Cooper, final run)
Novak free · Colby free · Colin free · Cooper free · exit 0. No Topic 1 or demo name (Elena, Carmen, Darnell, Reed, Jack, Molly, Liam, Reyes) appears in the three content files (grep 0). No other capitalised name appears in any student string (the only other capitalised words are Earth, Sun, Moon and the source citations in author-facing source fields).
Judgement calls
- Article lengths of 168–258 words. The coordinator's correction of 2 Oct (the 150-word cap is the SCRIPT's; Grade 3's approved articles run about 300) is followed: every example sequence is complete, every article stands alone, and a subtitle or figure breaks every run of at most eight idea lines. L05 is the longest (258) because it carries both named beliefs and the phone transfer; it is still under the 300-word WARN line.
- "Pitch" coined after the first pair (question 1 above).
- "Softer" for the loudness pair (question 2 above);
TOPIC["synonyms"]carries quieter so any later typed item accepts both. - L05's "could do without a video" — the capstone is scripted (149 words) and the call is James's; the article carries six figures including the lit, dark and phone-lit path drawings so it stands alone.
- The typed "nothing" item (PP-51) accepts "darkness", "the dark", "black" and "blackness": a child who writes "he sees black" has the verdict; the why gives the reason. Flagged for the blind read.
- "eye" typed (PP-48) accepts "i": a nine-year-old's spelling of the sound; listed rather than relied on the near-miss grader.
- The ruler scene is Grade 3 Topic 11's headache object, reused because the register names it as ENE4-031's example and the depiction already exists; L02's quiz never names a ruler, and the bank's one ruler item (L03-q9) is a sister-term sort, not a prediction on the taught case.
- The oblong arm in
basement_phone: an arm holds the phone (Grade 3's "no hands, an oblong arm" convention); no hand or face is drawn. - Two-option items in the bank: none — every bank MCQ has four options, so the yes / no claim items of the quizzes become verdict-fixed reason items in the bank (PP-21, 31, 54).
- Claim-makers are the topic's four characters, never in their own lesson's quiz (the Topic 1 precedent): Colby makes the SND-06 claim in L03's headache, Colin in its quiz; Colin makes the LGT-01 and LGT-02 claims in L05's quiz; Colby's claims there are TRUE.
Video batch (built, NOT sent — the coordinator's 2 Oct line)
Every lesson dict carries closing_bullets (two to four bullets of a few words, the rule split into its pieces; S38 reads them joined and finds a verb) and TOPIC carries summary_bullets (four chips). python3 build_tools_video_batch.py grade4/topic07_build/content/G4T07.py → handoff/G4T07/videos/batch_G4T07.json, 7 videos (intro, L01–L05, summary), prompts 4,297–5,478 characters, interactivity off, key string in video order A B B C A B A C (B 3 of 8); grep -c strand → 0. check_brief.py → L01–L05 and SUMMARY clean; the INTRO carries the one standing R79 hit (no closing bullets — an intro teaches nothing, so it has no rule slide), accepted and recorded in the tool's READY.md exactly as Topic 1's and the demo's. Nothing has been messaged to the Peps session.
Owed
Blind review (a non-author agent under review-questions and review-lesson; the type sheet and the bank's design-move inventory are in records/TYPES_G4T07.md); review-figures by a non-author on the 28 svg renders; the picture stage (7 placeholders through David's pack) after James answers the two questions and the text is reviewed; sending the video batch (built above; L05 at James's call) to the Peps pipeline, asked first; the topic page in course_preview/ (built to /tmp/g4t07_test.html here, not deployed). Nothing is committed, nothing has left this machine.
v2 — reviews applied (2 October 2026)
Skill: course-build → write-lesson (article and script lines) → write-mcqs (every item change) → write-explanation (fb / why / model lines) → sentence-atomise (every new sentence) → review-figures (author re-render, angles measured) @ b0fa825
In plain words. The three reviews of 2 October found nothing wrong with the science or the order of the lessons; they found places where the course
contradicted itself (the Moon called a light source), where the bank re-used scenes the lessons had already spent, where a typed question was not really
closed, where two items sat side by side saying the same thing both ways, and where a drawing let size stand for speed or let a bounce leave at a
different angle from the one it arrived at. Every Essential and Worth-fixing row is applied below; the Leave rows are left as they say. The three
files were edited in place; nothing is committed and nothing has left this machine.
#### Every finding → what changed
| Source | Finding | What changed (or why not) |
|---|---|---|
| Blind | L01-09 → L01-10 and PR-12 → PR-13: the MCQ printed "pitch" just before the typed item | The term MCQ now sits one item earlier: L01-q8 (the triangle boundary item is L01-q9, the typed term L01-q10); in the practice set the term MCQ is PR-11, the written answer PR-12, the typed term PR-13 |
| Blind | L02-02 → 03; L03-02 → 03 → 04; L04-03 → 04 → 05 restate the previous answer | Left: these are the (b) scaffold ladders the check-design records name; L04-01 → L04-11 was not, so L04-q11 is re-scened (candles and a birthday cake) and L04-q1's options are short and parallel |
| Blind | L02-09 / 10, L03-10 / 11, L05-05 / 06: the same claim both ways, adjacent | Each pair's second (or TRUE) claim is re-instanced on a fresh case: a thick and a thin string (L02-q9); a gong (L03-q11, the reviewer's row); under a thick blanket (L05-q6) |
| Blind | L04-06, L04-07, PR-08, PP-34, PP-35: the drawings' descriptions gave the verdict | _lettered_paths writes alt and blind text as letters and endpoints only ("K: two arrows, from the lamp to the cup, then from the cup to the eye"; "J: one arrow, from the eye to the cup"; "L: one arrow, from the lamp to the eye"); no "misses", no "on to" |
| Blind | L05-05, L05-06, PP-40, PP-41: "completely dark" items; a child who has seen in a dim bedroom will resist | L05 article: "A bedroom at night is never completely dark." / "A little light comes in, and that is what you see by." after the porch-light line; L05 script beat 6 says it |
| Blind | PP-04: a school bell's clang is also high | Re-optioned with a train horn's blare as the clearly low sound (the reviewer's row: a train horn, a goose, a wolf, an alarm) |
| Blind | "light source" leaned on but not on L04's page | L04 article: "The lamp makes its own light, and a thing that makes its own light is called a light source." before "The lamp is the light source…"; the script says "The lamp makes the light, so it is the light source" |
| Blind | PP-29 / PP-30 said "the air vibrates" | Not added to the lessons (air vibrating is Grade 3's travel lesson, not this topic's); the two items are re-scened on things that visibly vibrate — a glass tapped with a spoon (PP-30), a stamp on a wooden stage (PP-31) |
| Blind | PP-20 distance and pitch, untaught | Re-asked as "Which sentence is true?" over loudness only (a quiet sound can be high in pitch); distance is gone |
| Blind | the foghorn (PR-02, PP-02) untaught | Not named in L01 (that would spend a lesson example on a practice item); PR-2 is a lawn mower's rumble, PP-2's option the rumble of a ship's engine |
| Blind | bank give-away pairs | The ⟂ list in TYPES_G4T07.md now carries PP-5 ⟂ PP-19 ⟂ PP-45; PP-11 ⟂ every faster / slower item; PP-15 ⟂ every stronger / less-strongly item; PP-17 ⟂ PP-35; PP-18 ⟂ PP-42 ⟂ PP-44; PP-41 ⟂ PP-54; PP-20 ⟂ PP-21 |
| Blind | PP-20 "all three of these" first; PP-47 the longest stem | PP-20 re-asked (above); the four-hits item (now PP-48) is a trash can lid in two sentences |
| Blind | PP-51 accept "he can't see anything" | Overtaken: PP-51 is an MCQ (the review's Essential row), now PP-44 |
| Review | The Moon called a light source (L05 article, L05-q9) | "like a streetlight or a porch light" in the article, the option, every fb and why line; the lesson_type note names Grade 3 Topic 13's ruling |
| Review | PP-48 reused L04's lamp-and-book headache | Re-scened: a campfire and a log (the reviewer's candle was PR-8's source, so not used); accept list adds pupil / pupils and Cooper's forms; now PP-49 |
| Review | PP-46 reused L03's headache and needed two atoms | Replaced by one ENE4-032 item: two sleigh bells of the same size, one louder — the rule run backwards (now PP-47) |
| Review | fourteen reused scenes (PP-47, 52, 5, 42, 39, 3, 2, 35, 32, 25, 34, 41; PR-6) | Re-scened: a trash can lid (the reviewer's cymbal was already PP-27's) · a garage and a bike · a recorder and a trombone (the reviewer's piccolo and double bass were already PP-6's) · a seagull and a tractor · a cardboard play fort · a tiger and a robin · a ship's engine · the Sun and a rabbit · a violin bowed gently · two doorbells · a flashlight and a bucket on the grass (the reviewer's lantern is PP-35's; a boot / shoe drew too low to label, see figures) · a backpack in a dark hallway (the reviewer's coat is L05's attached closet) · PR-6 a cowbell (the reviewer's triangle is L01-q8's) |
| Review | the record's "every scene is FRESH" claim was false | Rewritten in the type sheet as a re-performed grep over 75 scene nouns against every lesson-side string, result printed (0 hits); its first run caught six more (PP-8 bells → metal bowls; PP-19 sings → a recorder; PP-22 big drum → cooking pots; PP-40 white wall and mirror → a brick wall and a silver tray; PP-43 coat → backpack; PP-49 candle → campfire) |
| Review | PP-43, PP-45 typed with the pair in the stem; PP-51 open | All three are four-option MCQs on the sister terms, medium: the tuning forks (PP-27), a bee beating its wings harder (PP-34), the cellar (PP-44, the reviewer's four outcomes) |
| Review | PP-14: a door knock IS low in pitch | "Cooper knocks on a door hard, then knocks gently…" — louder / higher in pitch / lower in pitch / quieter |
| Review | quiet / quieter against soft / softer | "quieter" and "quiet" throughout (L03's frame, chips QUIET, both tables, every option, fb and why; the intro's LOUD OR QUIET); TOPIC["synonyms"] = [["quieter", "softer"]]; "softly" stays for the blow of the whistle (an action, not a sound) |
| Review | L02 "it hums a low sound" after the coin | "its hum is low in pitch" (headache, article, script) |
| Review | L05 script beats 2 and 5 | Beat 2 "…but he sees nothing, however long he waits."; beat 6 "At night a bedroom is never completely dark: light from a streetlight comes in, and that is what you see by."; the script re-cut to 150 spoken words |
| Review | L02 article: no "higher in pitch, not louder" mirror | "The sound is higher in pitch, not louder." after the band |
| Review | L03-q11 | Colin's SND-06 claim on a gong |
| Review | L05-q3 | "Colby stands deep inside a completely dark cave. Why does he see nothing?" (stands alone) |
| Review | L05-q11 option c | "nothing at all" |
| Review | PP-34 / PP-35 option d | A fourth lettered path on each figure (one arrow from the thing to the eye, no arrow from the source), letters T U V W and E F G H; now PP-36, PP-37 |
| Review | PP-54 | "Which sentence says what really happens?" — four options in one frame, two "You see nothing, because …" and two "You see a little, because …" |
| Review | PP-49 | "Which pair of arrows should he have drawn?" — four arrow pairs; now PP-50 |
| Review | PP-39 / PP-52 keys | Shortened and parallel: "No light reaches his eye." (PP-41); "Light from the door bounces off the bike to his eye." (PP-52) |
| Review | PP-20 | "Which sentence is true?" (above) |
| Review | PP-26 | "making the string vibrate more slowly" replaces the distance option |
| Review | PP-36 | "For him to see the deer, where must the light bounce off?" (now PP-38) |
| Review | PP-4 | a train horn, a goose, a wolf, a smoke alarm |
| Review | L04-q1 | "when light from it reaches your eye / when your eyes are open / when the thing is shiny" |
| Review | L05 h "Turn a light on" | "A light comes on" |
| Review | intro beat 4 | "Nothing seemed to touch his ears, and nothing seemed to touch his eyes." (blurb and script; the intro trimmed to 118 words) |
| Review | Leave rows | L03 / L05 check_design names corrected (Miss Novak makes L03's TRUE claim, Colin the SND-06 claim; Colin makes both L05 belief claims, Colby the TRUE one); "pupil / pupils" added; L03-q9, PP-31 (now PP-32), L01's "A low sound is deep" left |
| Figures | pitch stills drew speed as size | _ruler_panel, band_tight, rule_faster, ruler_long_headache: the same strokes (gap 5) and ghost (5) on every panel; the animation's two swings have the SAME amplitude (5°) and differ only in period; the loose band sags and the tight band is straight, so the two panels differ in the thing itself; register updated |
| Figures | the reflection clamp (angle in ≠ angle out) | The clamp is gone: _bounce asserts the bounce point lies on the thing and that the two angles agree; _eye_y_for finds the head height that puts the bounce on the thing; the basement scene is rebuilt (bulb at x 120, the box on a low shelf at x 300, head at (400, 130)); the phone's light bounces off the box's RIGHT face. Measured on the drawn end points: basement_lit 31.1 / 31.1 · basement_phone 41.9 / 41.9 · mirror_book_same book 36.5 / 36.5, mirror 44.2 / 44.2 · path_headache, path_step1, path_step2, rule_path 14.4 / 14.4 · path_tree 28.6 / 28.6 · pp_paths_bucket 45.2 / 45.2 · pp_paths_rabbit 44.4 / 44.4 · pr_paths_vase 16.9 / 16.9 · q_paths_cup 22.9 / 22.9 · q_paths_dog 35.2 / 35.2 |
| Figures | light sources floating; the flashlight with no arm | The lamp and the candle stand on the table top (base at T; the candle moved beside the vase so the bounce is visible); the cup item's lamp faces right (Topic 13's other pose) so that scene is not flat; the flashlight is held by an oblong arm in _source and in both panels of mirror_book_same; the phone's arm redrawn |
| Figures | drum_two_headache, basement_dark placed nowhere | Placed: L03's article after "Is he right?" (the headache figure with the answer's layer off) and L05's article after "The box is right in front of him." |
| Figures | text out of frame | rule_card wraps every line at the measured width and asserts the fit (rule_path, rule_dark, rule_faster, rule_louder all wrap); table_fig asserts the table fits the 540-unit phone column — both tables' cells shortened ("drum, tapped gently"; "band, pulled tighter"), 506 and 484 wide |
| Figures | smaller rows | ONE LIGHT SOURCE chip on path_step1 (the leader chip; the verdict chip dropped); basement_lit's question at the top, the ray clear of it; letter chips sit beside their path, never on a line or the table edge (the taught path's chip beside its first arrow, the eye-beam's under its line near the eye, the glow path's beside its start, the missing path's above); the drum's strokes sit above the skin near each rim end with a dashed ghost, nothing on the shell, the stick steep from the upper right clear of the chips; q_paths_cup's alt says "cup"; every line that reaches the eye now carries its head AT the eye (frac 0.96), so the alts are true; the eye-beam arrow ends at the thing's side (the vase at its widest, 22 below the top) |
#### Counts (v2)
5 lessons · scripts 147 / 150 / 139 / 143 / 150 spoken words (cap 150) · intro 118 words · summary 153 · articles 186 / 177 / 203 / 245 / 279 words (none above the 300 WARN line) · 55 quiz items (10 + 10 + 12 + 11 + 12) · 13 practice items · PP100 bank 54 items: 11 / 12 / 12 / 11 / 8 per atom; 18 easy · 26 medium · 10 hard; 50 four-option MCQs, 2 typed (pitch, eye), 2 multi-selects · 35 figures (28 svg, 2 photo placeholders, 5 cartoon placeholders; pp_paths_ball and pp_paths_cat replaced by pp_paths_bucket and pp_paths_rabbit).
#### Key strings (v2)
- Attached questions in video order (L01–L05, summary 1–3):
0 1 1 2 0 1 0 2(unchanged). - Lesson quizzes, two-option items: L01
0 1 1 0 0 1 1 0· L020 0 1 1 1 0 0 1· L030 1 1 1 1 0 0 0 1· L040 1 1 0· L051 1 0; three-option: L011· L020 0· L031 2 1· L040 0 1 1 2 1 2· L051 2 0 2 0 1 1 0; practice two-option0 1 1 1 0, three-option1 1 0 1 0 2. - PP100, 50 MCQs in bank order:
C A B D B C D B A D B B A D A A A C B C C A B D A C D D A C B B D B C C A D C B A B D C A C D B D A— A 13 · B 13 · C 12 · D 12 (max 26 %). - Bank renumbering (old → new): 1–26 unchanged · 27–32 → 28–33 · 33 → 35 · 34–41 → 36–43 · 42 → 45 · 43 → 27 · 44 → 46 · 45 → 34 · 46 → 47 · 47 → 48 · 48 → 49 · 49 → 50 · 50 → 51 · 51 → 44 · 52–54 unchanged.
#### Checker results (v2)
python3 build_tools_check_topic.py grade4/topic07_build/content/G4T07.py→ 0 FAIL, 49 WARN, all S36 words. The nine new words answered: gong (a school music-room instrument; fine), growls / blare / blares (the sounds named; fine), trombone and violin (US school-band instruments; fine), seagull (fine), jingles and wobbles (everyday; fine), trash (trash can lid; the US word). The forty v1 words stand as answered in v1.python3 grade4/check_g4_articles.py grade4/topic07_build/content/G4T07.py→ 0 FAIL (L05's script 150, the intro 118).python3 build_tools_names.py Novak Colby Colin Cooper→ all four free, exit 0.python3 build_tools_build_topic_site.py grade4/topic07_build/content/G4T07.py /tmp/g4t07_v2.html→ 5 lessons, 13 practice, 54 pp100, 35 figures.python3 build_tools_video_batch.py grade4/topic07_build/content/G4T07.py→ 7 videos, key stringA B B C A B A C;check_brief.py→ L01–L05 and SUMMARY clean, the INTRO's one standing R79 line (no closing bullets: an intro teaches nothing), as in v1;grep -c strand→ 0. Not sent.- Figures:
python3 content/figures.py /tmp/g4t07_figs/v2writes 35 SVGs and prints the fourteen measured angle pairs (above, every pair equal);/tmp/g4t07_figs/render_v2.shrenders every figure to PNG at 1000 px with headless Chrome; opened and read:q_paths_cup,q_paths_dog,pr_paths_vase,pp_paths_bucket,pp_paths_rabbit,path_step1,path_step2,path_tree,rule_path,mirror_book_same,basement_lit,basement_phone,eye_beam_wrong,rule_dark,ruler_long_headache,ruler_anim,rule_faster,band_tight,drum_two_answer,rule_louder,table_vibration_loud. No frame wider than 560; no text outside a frame; no chip on a line or a table edge. - Old names grepped after the renames:
pp_paths_ball,pp_paths_cat,pp_paths_shoe,_three_paths, "foghorn", "the Moon" (student text), "softer" / "soft" (student text) → 0 in the three content files.
#### Questions for James — built as recommended
- Coin "pitch" after the first pair — the reviewer agreed ("pitch" names a scale; the sort cannot be voiced until the scale has a name). Built: after the first pair, as in v1.
- "Quieter", not "softer" — the reviewer's answer: Grade 3 Topic 11 says quiet / quieter fifteen times, the atom says "louder or quieter", "soft" has a second everyday reading. Built: "quieter" / "quiet" throughout, "softer" kept in
TOPIC["synonyms"]. About 60 strings changed.
#### Items whose stem, options, key, model, figure or accept list changed (the coordinator re-reads exactly these blind)
- Lessons: L01-q8 and L01-q9 (the term MCQ and the triangle item swapped places; the MCQ's fb says "loud or quiet") · L02-q9 · L03-q5, L03-q6, L03-q7, L03-q8 (options "quieter" / "quiet"), L03-q11 · L04-q1, L04-q6 (figure), L04-q7 (figure), L04-q11 · L05-q3, L05-q6, L05-q9, L05-q11. Attached and summary questions: unchanged.
- Practice: PR-2 · PR-6 · PR-8 (figure) · PR-11 and PR-12 (the term MCQ and the written answer swapped places; the MCQ's fb says "loud or quiet"). PR-13 unchanged.
- Bank (new ids): PP-2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 19, 20, 21, 22, 24, 25, 26, 27, 28, 30, 31, 32, 33, 34, 36 (figure), 37 (figure), 38, 40, 41, 43, 44, 45, 47, 48, 49 (accept list), 50, 52, 54. Unchanged in content, renumbered only: PP-29, 35, 39, 42, 46, 51. Unchanged in content and id: PP-1, 12, 16, 17, 18, 23, 53.
- Figures redrawn (every one re-rendered and read): ruler_long_headache, ruler_anim, band_tight, rule_faster, drum_two_headache (placed), drum_two_answer, rule_louder, table_vibration_pitch, table_vibration_loud, path_headache, path_step1, path_step2, mirror_book_same, path_tree, rule_path, q_paths_cup, q_paths_dog, pr_paths_vase, pp_paths_bucket (new), pp_paths_rabbit (new), basement_lit, basement_dark (placed), eye_beam_wrong, basement_phone, rule_dark.
#### Not applied, and why
- "The air vibrates" was not written into L01–L02: the lessons teach pitch and loudness of the vibrating THING; air's part is Grade 3's travel lesson. The two bank items that leaned on it are re-scened instead.
- The foghorn was not named in L01: naming it would spend a lesson example on a practice item; the practice item and the bank option are re-scened.
- Three of the reviewer's fresh scenes were not used because the bank already held them or a lesson did (a cymbal → PP-27; a piccolo and a double bass → PP-6; a coat → L05's attached closet; the triangle → L01-q8; the lantern → PP-35; the candle → PR-8); the nearest fresh thing was used in each case, listed above.
- A shoe (the Grade 3 Forces drawer's glyph) was tried for the bank's flashlight scene and dropped: on a table it sits too low for a letter chip to clear the table edge; a bucket on the grass took its place and is registered.
#### Owed after v2
The coordinator's blind re-read of the ids above; the picture stage (7 placeholders) after James's sign-off; sending the batch to the Peps pipeline (asked first). Nothing is committed; nothing has left this machine.
v3 — polish (2 October 2026, from Reader C's re-read of the v2 bundle)
Skill: course-build → write-mcqs → write-explanation → sentence-atomise (every new sentence) @ b0fa825
In plain words. The re-read agreed every key. It left four small things, all applied here: one bank item had a second true sentence, one bank item was another item with the room renamed, and two practice items repeated a quiz item's scene word for word. The accept lists already carried every form the reader asked for.
- PP-03 — the stem now asks "Which sentence about pitch is true?", so "The tiger's growl is louder than the chirp" (true in the world) is ruled out by the stem itself; the why's last line says the loudness sentence is not about pitch. Key unchanged (B in bank order).
- PP-44 — a different move from PP-18 (no longer "what is seen with no light"): Colby, in a cellar with no windows and its light off, bends a glow stick until it glows green; what does he see? Key: "the glow stick and the shelves near it, dimly"; distractors "nothing at all" (a lamp must be on), "only the glow stick" (only the source is seen; the bounce missed), "everything in the cellar, clearly" (a little light over-read). Key position unchanged (C). Type sheet: the inventory row and the ⟂ list updated (PP-18 ⟂ PP-42 only).
- PR-09 — same recall move as L04-02, fresh scene: "Sunlight hits a red barn and bounces off it." (was a wall, L04-02's flashlight-on-a-white-wall scene); fb and why follow.
- PR-11 — same term move as L01-08, fresh scene: "A fire truck's siren wails a high sound, and a pig grunts a low sound." (was L01-08's bare "A sound can be high or low."); the why names the siren and the grunt.
- Accept lists — checked, nothing to add:
PITCH_ACCEPT(bank and L01-q10) already holds "the pitch", "pich", "picth", "pitsh";EYE_ACCEPT(PP-49) already holds "his eye", "eyes", "eyeball", "eye ball". - Scene nouns grepped across the three content files before use: barn 0, sunlight 0, siren 0, fire truck 0, pig 0, glow stick 0.
Changed ids: PP-03, PP-44, PR-09, PR-11. Key strings unchanged (PP100 50-MCQ string and the practice strings as in v2).
Checks: python3 build_tools_check_topic.py grade4/topic07_build/content/G4T07.py → 0 FAIL, 52 WARN (all S36; the three new words wails, grunts, grunt are the sounds named, fine) · python3 grade4/check_g4_articles.py grade4/topic07_build/content/G4T07.py → 0 FAIL · python3 build_tools_build_topic_site.py grade4/topic07_build/content/G4T07.py /tmp/g4t07_v3.html → 5 lessons, 13 practice, 54 pp100, 35 figures · python3 build_tools_blind_bundle.py … grade4/topic07_build/blind/2026-10-02-v3 → 130 items held (122 mcq, 4 text, 2 frq, 2 multi).
Owed after v3: a cold read of the four changed ids on the v3 bundle; the picture stage (7 placeholders) after James's sign-off; sending the video batch (asked first). Nothing is committed; nothing has left this machine.
Guidance, questions and accuracy review (2 October 2026)
Skill: course-build → review-lesson (Role B, B2) → review-questions → review-accuracy (non-author pass; filed by the coordinator from the reviewer's hand-back) @ b0fa825
Topic 7 — guidance, questions and accuracy review, 2 October 2026
The science is right and in order; the five scripts are in good shape. Four things to fix before the keys are trusted: (1) the Moon is called a light source (Grade 3 Topic 13 taught, with an item, that it is not — Essential); (2) the bank is not fresh: fourteen items reuse a lesson, practice or intro scene, and the record's "every scene is FRESH" claim is false on re-performance; (3) three typed items are not honest typed items (PP-43, PP-45 have the pair in the stem; PP-51 "type what he sees" rejects "he can't see anything"); (4) two words for one thing: L01 says quiet / quieter, L03 and the bank soft / softer.
The reviewer's view on the two questions for James: coin "pitch" after the first pair — yes, as built ("pitch" names a scale, and "High and low always name their quantity" means the sort cannot be voiced until the scale has a name). "Quieter", not "softer": Grade 3 Topic 11 uses quiet / quieter fifteen times, the atom's behaviour says "louder or quieter", "soft" has a second everyday reading; keep "softer" in synonyms so a typed "softer" is accepted; about 60 strings change.
| where | finding | rule broken | severity | the rewrite |
|---|---|---|---|---|
| L05 article "like a streetlight or the Moon"; L05-q9 | the Moon as a light source | course against itself; LGT-06 | Essential | "light is coming from somewhere, like a streetlight or a porch light"; q9 option "from a streetlight or a porch light" |
| PP-48 | L04's own lamp-and-book headache | fresh instance | Essential | a candle, a plate, Cooper: what part of him must the light reach? |
| PP-46 | L03's headache (Cooper hits a drum harder); needs two atoms | fresh instance; one atom per item | Essential | re-scene on one atom (banjo strings: which is higher in pitch?) or move to the strand test |
| PP-47, 52, 5, 42, 39, 3, 2, 35, 32, 25, 34, 41; PR-6 | lesson, practice and intro scenes reused (drum skin; basement box; flute and tuba; zipped tent; the intro's owl; foghorn; cat; bowed cello; bicycle bell; flashlight and ball; box and flashlight; xylophone bar) | fresh instance | Worth fixing (Essential as a set) | the reviewer's fresh scenes: a cymbal; a garage and a bike; a piccolo and a double bass; a cardboard play fort; a cow and a chick; a ship's engine; a rabbit; a violin bowed gently; two doorbells; a lantern and a boot; a coat in a dark hallway; a triangle rung harder |
| TYPES / BUILD_RECORD "Every scene is FRESH" | false on 14 items | a record's claimed check is re-performed | Essential | rewrite the paragraph with the noun grep printed |
| PP-43, PP-45 | typed "higher / lower", "louder / softer" with the pair in the stem | a typed answer only where the question is closed | Essential | four-option MCQs on the sister terms, medium; PP-45 re-scened (a bee beating its wings harder, not flying close past) |
| PP-51 | "type what he sees" rejects "he can't see anything" | same | Essential | MCQ: nothing / the shelves, faintly / only the nearest thing / only his hands |
| PP-14 | a door knock IS low in pitch: a second key | second defensible option | Essential | "Cooper knocks hard, then gently…" quieter / louder / higher in pitch / lower in pitch |
| L01 vs L03 and bank | quiet / quieter against soft / softer | one word for one thing | Worth fixing | quieter throughout; "softer" in synonyms |
| L02 headache and script "it hums a low sound" | after the coin | high and low name their quantity | Worth fixing | "its hum is low in pitch" |
| L05 script beats 2, 5 | "however long he waits" and the night-time source article-only | video and text each teach the whole part | Worth fixing | beat 2 "…but he sees nothing, however long he waits."; beat 5 "At night you see a little because light comes from somewhere, like a streetlight." |
| L02 article after the band | no "higher in pitch, not louder" mirror | SND-06 confronting case | Worth fixing | add "The sound is higher in pitch, not louder." |
| L03-q11; L05-q3; L05-q11 opt c; PP-34 / PP-35 opt d; PP-54; PP-49; PP-39 / PP-52 keys; PP-20; PP-26; PP-36; PP-4; L04-q1; L05 h "Turn a light on"; intro beat 4 | give-aways, verdict + reason options, key tells, "all three of these", duplicate options, a stem true of more than one thing, a staging subtitle, "nothing touched his ears" | the standing rules | Worth fixing | as the reviewer's table: a gong claim; a cave stem that stands alone; "nothing at all"; a fourth lettered path; "Which sentence says what really happens?"; four options as arrow pairs; shortened keys; "Which sentence is true?"; "vibrate more slowly"; "where must the light bounce off?"; a train horn, a goose, a wolf, an alarm; parallel short options; "A light comes on"; "Nothing seemed to touch his ears" |
| L03 / L05 check_design names; PP-48 accept "pupil"; L03-q9; PP-31; L01 fb "A low sound is deep" | Leave | — | Leave | record lines corrected; add pupil / pupils |
Figure review (2 October 2026)
Skill: course-build → review-figures (non-author pass on the 35 figures, rendered with headless Chrome at 1000 px, angles measured) @ b0fa825
Topic 7 — figure review, 2 October 2026 (filed by the coordinator from the reviewer's hand-back)
No rejects; two register faults each touch several figures.
- The pitch stills draw speed as size, which L03 then teaches as loudness. In
ruler_long_headache,rule_fasterandband_tightthe slow thing gets wide motion strokes and the fast thing narrow ones; L03 coins stroke spread = how strongly it vibrates = how loud, so the short ruler and the tight band read as "vibrates a little → soft". Fix: the same gap and ghost on both panels; the chips carry FASTER / SLOWLY. - The reflection geometry is clamped, so angle in ≠ angle out in most light-path drawings (lamp → book 29° in / 21° out;
q_paths_cup29 / 15;pr_paths_vase23 / 8;pp_paths_ball29 / 16;path_tree24 / 20;basement_lit74 / 4;basement_phone19 / 4). Grade 3 Topic 14's register and James's 29 September rule require equal angles. Fix: replace the clamp in_path_scenewith an assert and reposition;basement_phonebounces off the box's right face. - Light sources float 60 units above the table (
lamp(110, floor-60),candle(90, floor-60)); passT. The flashlight floats with no arm in two figures (an oblong arm). - Two figures placed nowhere:
drum_two_headache,basement_dark(no screen line names any(figure key)); the record claims the first is L03's headache. - Text out of frame:
rule_pathboth rule lines;rule_darkbold line;table_vibration_loud584 wide. - Smaller: LIGHT SOURCE printed twice on
path_step1;basement_lit's ray runs through the question text; letter chips sit on the light line (P, W, K) or the table edge (J, T);band_tight's chip hides a stroke and the two bands are drawn identical;drum_two_answer/rule_louderstrokes on the shell, stick under the chip;q_paths_cupalt says "mug"; "arrowhead at the eye" alts where the head is mid-line; the R arrow ends inside the vase.
Passed: item letters J–Y never A–D; key position varies; one gold for every path, no colour tracks a key; no hand or person glyph; eye_beam_wrong the only line leaving an eye, crossed in red and labelled wrong; no alt names a key; no caption says "real"; every IMAGE_KINDS key exists, all seven photo / cartoon keys briefed with an eye line.
Best: eye_beam_wrong, mirror_book_same, basement_no_light. Weakest: basement_lit, rule_faster, rule_path. Renders: /tmp/g4t07_figs/*.png.
Blind read, re-read and polish flags (2 October 2026)
Skill: course-build → review-lesson (Role A blind key read, two readers; Role C adjudication by the coordinator) @ b0fa825
Topic 7 — What reaches your ears and your eyes — blind read, 2 October 2026
Every key agreed by two blind readers. Bundle: 119 MCQ, 7 typed, 2 written, 2 multi-select; 130 items. Adjudication: A agree 126 of 126 machine-matched, B 126 of 126; MCQ disagreements 0, typed off-list 0. By hand: PP-50 (C, D) and PP-53 (A, D) match both readers; the written items carry their models' points. Adversarial: add "he can't see anything" / "can't see anything" to PP-51 (the "nothing" item); "the pitch of the sound" is a reader form the list already covers with "the pitch".
Flags carried into the fix pass
| Item | Who | Flag | Ruling |
|---|---|---|---|
| L01-09 → L01-10; PR-12 → PR-13 | A | the MCQ prints "pitch" just before the typed item | separate by one item; the recall stem describes without printing |
| L02-02 → 03; L03-02 → 03 → 04; L04-03 → 04 → 05; L04-01 → L04-11 | A, B | the next stem restates the previous answer | these are the scaffolded (b) ladders by design where the record says so; where not, re-set the scene in each stem |
| L02-09 / 10; L03-10 / 11; L05-05 / 06 | A, B | the same claim both ways, adjacent | keep one, or re-instance the second on a fresh case |
| L04-06, L04-07, PR-08, PP-34, PP-35 | B | the drawing descriptions say which path goes source → thing → eye | the blind text and alt must describe the three paths without the verdict (letters and endpoints only) |
| L05-05, L05-06, PP-40, PP-41 | A, B | "completely dark" items: a child who has seen in a dim bedroom will resist | one sentence in L05's article and video: "A bedroom at night is never completely dark; a little light comes in, and that is what you see by." |
| PP-04 | A, B | a school bell's clang is also high; only the alarm's "thin and sharp" cue decides it | re-option with a clearly low sound (a tuba note; a bass drum) |
| L04-02 distractor, PP-37 key "light source"; PP-29 / PP-30 "the air vibrates"; PP-20 distance and pitch; PR-02 / PP-02 foghorn | A, B | terms and facts the items lean on must be on the lesson pages | check L04's article coins "light source" and L01–L02 say the air vibrates; PP-20 cut or re-asked; the foghorn named as a low sound in L01 |
| PP-05 / PP-19 ⟂ PP-42; PP-11 ⟂ faster / slower items; PP-15 ⟂ stronger / softer items; PP-18 ⟂ PP-40 ⟂ PP-51; PP-39 ⟂ PP-54 | A | bank give-away pairs | ⟂ draw constraints in the type sheet |
| PP-20 "all three of these" first; PP-47 longest stem | A, B | un-exam-like | re-option; trim |
Readers' files: blind/2026-10-02/READER_A.md, READER_B.md.
v2 re-read, 2 October 2026 (Reader C on blind/2026-10-02-v2, the whole bundle)
Every key agreed (130 items; MCQ disagreements 0; both multi-selects PP-51 B, C and PP-53 A, B matched; typed answers on the lists; both written items in the key's words). The redrawn path descriptions (the arrows are the data) gave nothing away and lacked nothing. Flags to the polish pass: PP-03 has two defensible options — "the tiger's growl is louder than the chirp" is true in the world, and the stem asks only "Which sentence is true?" (ask "Which sentence about pitch is true?" or swap A for a loudness claim the stem rules out); PP-44 is PP-18 with the room renamed (change one item's move); PR-09 = L04-02 and PR-11 = L01-08 (mixed practice as fluency repetition — keep on purpose or re-scene); L05-05 and PP-42 rest on "completely dark" meaning no light, which the lesson teaches (watch, do not change). Accept: "the pitch", "pich" / "picth" / "pitsh"; "his eye", "eyes", "eyeball". Reader's file: READER_C.md.