Topic 26 "How Earth's parts act on one another" — your read (2 October 2026)

Two readers answered 106 items cold and agreed every key. Their flags, all applied in v2: a bank item whose ash was "blown high into the air" sent a child to the air (the stem now says the ash is rock and settles on a lake); a two-of-four select where mud made a third part defensible (the geese now churn the water into waves); a hawk in a field with nothing said about the field (the field "is left as it was"); a lettered map whose description did not place both towns beside the lake (both now touch it); one lesson line for snow, hail and clouds as the water part; one recall stem that nudged toward deposition; a hard chain item stitched from two quiz items and three claim items on the lesson's own scenes (all re-scened); "key", "map key" and misspellings on every typed "legend" item.

Reader C then read the whole v2 bundle, 113 items, and agreed every key; the v1 fault is gone (no map description hands over the river's direction; the direction comes from the taught rule, recalled on the same page). Two items would not ship as they were, both fixed in v3: PP-22's description never said the river line passes the towns (it does now), and L04-02 left "ash is rock" to the lesson (the stem says it now). Reader C's cross-item notes, all applied: Luna and Lyla read as one child (Lyla is now Josie); L02-02's key was the only option with "and" (a distractor has one now); two yes in eight claims (three now). Reader C confirmed the parts sort is one honest bin each throughout (ash and dust are land; snow, hail, cloud and rain are water), that "say the acting part first" is applied the same way in every two-part item, and that every recalled word (erosion, deposition, weathering, precipitation, landslide) sits first in its quiz.

A sound topic, the reviewer said: three honest lessons on one walk, a clean four-part vocabulary with no sphere names, keys that all hold, Topic 20 and Topic 24 recalled word for word. Then the faults, all applied in v2: the videos never spoke two ideas the quizzes key on (the hawk-and-mouse boundary; the hills' long line), so both scripts gained a line; three bank items were quiz scenes with the nouns changed (re-scened); a wind-dries-a-pond pair was the evaporation case the type sheet bars (now wind blows spray off a waterfall); every map's alt and blind text said the river runs "from the brown shapes to the blue area", the answer to three items (now "joining"); three claim keys had two clauses and five hard items had the longest key (equalised; the checker reads 0 of 108); the third lesson ran to 392 words (split into L03 and L04); three practice items were quiz stems word for word (re-scened). Left as built: "all water is blue", rivers run to the sea, "legend" with "key", the boundary sentence, water-on-air excluded, the multi-selects.

A clean, friendly map, the reviewer said: cream sheet, brown hills along one edge, a blue sea with a scalloped coast, one river, a legend that matches every colour and shape, an N arrow. Four fixes, all made in v2: a brown hill sitting in the sea on six item maps (the hills band now stops short of the sea); alt and blind text that handed over the river's direction (now "joining"); a legend and letter chips unreadable on a phone (text raised, then in v3 the legend became a strip along the bottom at 13 px); a three-column table at about 5 px cells on a phone (two stacked two-column tables). Three unplaced pair cards deleted. Minor: the LAND card's corners, one legend over the coast, chips touching things, one town straddling the river, the parts' order, the side-view lake, the character pointer on the cartoon briefs, one arrow's tail. All done.

53 items in content/G4T26_pp100_bank.py: 49 four-option MCQs, two typed words ("legend") and two two-of-four selects. Per atom: EAR4-026 15 · EAR4-080 17 · EAR4-081 21. Easy 21, medium 17, hard 15, sorted easy to hard and rising with the atom's place in the topic. MCQ keys A 13 · B 13 · C 12 · D 11. Twelve question types, one exemplar each on the type sheet: what a map or its legend shows; which letter marks the town, the sea, the lake or the forest on a fresh map; where both towns sit, which way the river runs, what sits between two things, and Luna's side-view claim; the name of the box, typed; which of four things is one of Earth's four parts; which of four events is one part acting on another; a child's claim about the parts, the correct reason; the word for one part acting on another; which part is doing the acting or being changed; which two parts act (and a two-step event, hard); select the two parts; a child names the changed part first, the correct reason. Every scene is fresh against the lessons, the quizzes and the practice (the scene-noun grep is in the build record).

Skill: course-build → write-lesson (L01 routine; L02 concept introduction in the fact form; L03 example-sequence classification capstone) → write-example-sequence, design-check-sequence, sentence-atomise, write-explanation; write-mcqs (quizzes, practice, PP100 bank + type sheet); write-video-script (intro, three lesson scripts, summary); review-figures (author self-check only) @ efd8fba

Grade 4 Topic 26 — How Earth's parts act on one another — build record (v1, 2 October 2026)

What this is, in plain words

Three lessons for nine-year-olds, built on one walk Miss Nakamura's class takes to the sea. At the start, Louis holds a map and Luna cannot find the river on it: the first lesson teaches that a map shows the land from straight above and that the legend says what each colour and shape stands for. By the river the path has fallen in: the second lesson names Earth's four big parts in everyday words (the land, the water, the air, the living things) and shows them acting on one another — the river carried the bank's soil away, the wind made waves, roots held the hill's soil, rain made the grass grow — and coins "interaction" last. At the beach a tall pile of sand has grass on top: the third lesson gives the two questions that spot the interaction (which part is doing the acting? which part is being changed?) and runs them on the pile, the grass, a beaver dam, a river mouth and a flooded field. No sphere names; the acting part is always said first and drawn on the left.

Counts. 3 lessons · 3 scripts (148 / 148 / 148 spoken words) + intro (109 words, 2 question marks, coins nothing) + summary (119 words, opens "Here's everything we found out about how Earth's parts act on one another.") · 3 attached questions + the intro's poll + 3 summary questions · 32 quiz items (10 + 11 + 11) · 15 practice items (12 MCQ, 1 typed, 1 written answer, three retrievals from Grade 3 Topics 24 and 26 and Grade 4 Topic 23; "legend" offered then typed, "interaction" recognised by MCQ) · PP100 bank 53 items (49 four-option MCQs, 2 typed, 2 multi-select; EAR4-026 15 · EAR4-080 17 · EAR4-081 21; easy 15 · medium 23 · hard 15; MCQ keys A 13 · B 13 · C 12 · D 11) · 42 figures (31 SVG by code, 8 photo placeholders, 3 cartoon placeholders) · articles 306 / 373 / 392 words (WARNs answered below) · build_tools_check_topic.py 0 FAIL, 33 WARN (every WARN answered below) · check_g4_articles.py 0 FAIL · check_svg_ids.py PASS (0 ids) · names register exit 0 · page builds (/tmp/g4t26.html: 3 lessons, 15 practice, 53 pp100, 42 figures; every article and quiz route screenshotted, no missing figure) · blind bundle cut (99 MCQ, 4 typed, 1 written, 2 multi) · video batch built, check_brief.py clean except the INTRO's standing R79 hit, grep -ci strand 0 · NOT sent.

Decisions made without a blueprint

• Three lessons, one per atom, on one running scene (a class walk to the sea). Reason: the atoms chain (read the land → the land's parts act → spot which act), and one walk lets each lesson re-set its scene in one sentence as James asked of the Grade 4 demo.
• L01 is a routine lesson, not a concept lesson. Reason: EAR4-026 is typed Routine; the routine is rebuilt from facts the child can hold (from straight above; the legend; all water is blue so the SHAPE tells which water; rivers run to the sea).
• L01's headache figure is the teaching map with the legend and north arrow switched off. Reason: the headache is "where is the river?", and the legend is the answer's layer (vault: a headache figure is the teaching figure with the answer's layer off).
• One side-against-above drawing confronts "a map is a picture from the side". Reason: Liben and Downs 1989 — young children read maps as pictures; one minimal pair (the same hill and lake) teaches the view.
• "legend" is coined in L01 and typed (synonym "key" accepted); "interaction" is coined in L02 and recalled by MCQ (RECALL_BY_MCQ). Reason: the brief's 9+ letter rule; "legend" is six letters a nine-year-old can spell.
• No "feature" coined. Reason: Grade 3 Topic 34 coined "feature" as a part of an animal's body; a second meaning would break One name per concept. The lessons say "each thing on the map".
• L02 is a concept introduction in the FACT form, examples only, with ONE boundary sentence (a hawk catching a mouse is inside one part). Reason: the fact is true of every case (no honest minimal non-example exists — the Forces log's rule), but the within-one-part case is the near miss a child meets, so it gets its sorting sentence before any check sorts it.
• The four parts get everyday names and no sphere names. Reason: the register's cross note (EAR5-025 re-enters with the names at grade 5-8).
• The acting part is ALWAYS said first and drawn on the left; one arrow, one head, one size. Reason: the direction is the only hard thing in EAR4-081; a fixed order teaches it without a second convention. Stated in the figures register.
• L03 is an example-sequence classification on one frame ("Which part is doing the acting? Which part is being changed? So the X acts on the Y."): the pile of sand (air on land) → the SAME sand with grass (living things on land: one feature changes, the acting part) → a beaver dam (living things on water) → a river mouth (water on land) → a flooded field (water on living things). Reason: minimal difference between the first two frames teaches "which part acts" is the thing that varies; the three photos the brief named carry the rest.
• L03's quiz is type (b) scaffolded → bare. Reason: the sort needs two decisions in order (design-check-sequence: a two-decision classification is drilled step by step, then bare).
• Water-on-air is never asked as a pair item. Reason: the direction (the water goes into the air; the Sun does the warming) is arguable for a nine-year-old and the lesson did not teach it; the belief "water never leaves the sea" is still confronted in a bank claim item, where the key is the Topic 24 fact.
• Every lesson gets a video. Reason: L01 shows a drawing being read, L02 shows four interactions as arrows, L03 shows the frame run twice on one pile of sand — each is a motion or a build the article can only still.

Neighbouring topics read as built (not blueprints): Topic 20 (G4T20.py: weathering / erosion / deposition — "Erosion carries the broken pieces away to somewhere new." recalled word for word in L02 and L02-q1; "the sand piled up where the wind slowed down" uses Topic 20's deposition idea in plain words), Topic 22 (the latest Earth topic; its map convention — a flat sheet from above, a town as dark squares — is imported, and its structure is the model), Topic 23 (G4T23.py: precipitation / collection / the water cycle — PR-3 recalls "Water falling from clouds like this is called precipitation."). Topic 24 was NOT on disk (only its figures.py): the recall line "Rivers carry the water back to the ocean." (L01, L01-q1, L01-q7, PR-5, bank type 3) and "Most of the water that goes into the air evaporates from the ocean." (PP-44's why) are taken from Topic 24's rule cards in its figures.py — check both against Topic 24's lexicon when it lands. Grade 3 doorways: Topic 26 "Soil is made of broken bits of rock mixed with bits of dead plants and animals." (PR-1); Topic 24 "A landslide is a mass of rock or soil suddenly sliding down a slope." (PR-2); Topic 38 "A plant's roots hold it in the ground, and they take in water from the soil." (L02's roots line and L02-q2). Grade 3 has no map or landform lesson (the architecture was grepped), so L01 teaches map reading from the start.

The simplification, named: "ash is tiny pieces of rock from the land" (volcanic ash is rock and glass; "rock" is Grade 3 Topic 24's word); "a cloud is made of tiny drops of water" (Topic 23's wording); the four parts as a flat list with no overlaps discussed (soil holds air and water — not raised).

Questions for James (the build does not wait on them)

• Is "interaction" the right word to coin at grade 4, or should the lexicon stay at "one part acts on another"? Context: the register title says "Spot the interaction"; the word is eleven letters and recalled by MCQ only. Recommendation: coin it (the Grade 5 sphere lesson will need it); built that way.
• May the PP100 keep two typed "legend" items as its only typed tier? Context: the brief wants the hard tier typed where typing does a job; "interaction" cannot be typed at this grade, and a pair answer is not a closed term. Recommendation: yes — 2 typed + 2 multi-select + 11 hard MCQs; built that way.
• Should L02's one boundary case (a hawk catching a mouse is inside one part) stay in a fact-form lesson? Context: the Forces log says a universal attribute takes examples only; the within-one-part case is the one near miss children raise. Recommendation: keep it as one sorting sentence and one yes / no item; built that way.

Design-check-sequence records

`

Skill: design-check-sequence @ efd8fba

Part: L01 (one part)

Type: (a) — a one-step reading routine: look a colour or shape up in the legend, say where it sits.

Plan: 10 items — 1 recall (Topic 24: rivers carry water to the ocean, 3 opt) → what view a map shows (3 opt) → which letter marks the lake / the sea (3 letters, two fresh maps) → the pattern the hills make (3 opt) → where both towns sit (3 opt) → which way the river runs (3 opt) → Luna's claim (yes / no) → the term recognised (3 opt) → the term typed (last). Stems ≤ 2 sentences.

Belongs in practice/test instead: a four-letter map read; the typed term from a described box; a map claim by its reason.

Part: L02 (one part)

Type: (a) — a fact true of every case, drilled as recognise-the-part and is-this-one-part-acting-on-another yes / no.

Plan: 11 items — 2 recalls (Topic 20 erosion; Grade 3 roots) → which is one of the four parts (3 opt, the Sun and the Moon) → which part three things belong to (3 opt) → three yes / no cases (wind on corn; rain on dust; the hawk and the mouse as the within-one-part no) → three claims (Luna: separate places; Louis: living things never change the land; Lyla TRUE: the wind changes a lake) → the term recognised last (3 opt).

Belongs in practice/test instead: four-event "which is one part acting on another" items; claims by their correct reason; the term judged in use.

Part: L03 (one part)

Type: (b) — a two-decision classification (which part acts; which is changed) → scaffolded, then bare.

Plan: 11 items — one case (wind leans the pines) as three scaffold items marked scaffold=True (acting, 4 parts; changed, 4 parts; the pair, 4 pairs) → five bare pair items on fresh cases (landslide blocks a stream; snow bends branches; prairie dogs dig; a dust storm; volcano ash) → Lyla's direction claim (yes / no) → Luna's within-one-part claim (yes / no) → a transfer (rain soaks a hill, the soil slides).

Belongs in practice/test instead: two-step events; multi-select sets; direction claims by their reason.

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The key strings

• L01 three-option: C C A A B B C A (no position over 60 %); two-option: n (one claim). L02 three-option: A B B A B; two-option: y y n n n y (no four alternate). L03 four-option: A D A A D B A D C; two-option: n n. Practice: A B C B A B y n C B n B C. Attached questions in video order (L01, L02, L03, S1, S2, S3): B A C A B C (A 2 of 6). Bank MCQ letters A 13 · B 13 · C 12 · D 11.
• Order items: none. Lettered items: every letter list lives once in figures.py (Q1_LETTERS … PP4_LETTERS, PR1_LETTERS) and both the stem sentence and the drawing read it; letters are J–R; the drawer's convention is "the letter chip sits ON the thing it marks (centre of the lake oval, the forest patch, the hills band, the sea band, the river's midpoint; just below a town's squares)".

The example sequences, written out

L01 (a routine, run once on Louis's map): the view (from straight above; the side-against-above pair) → the legend (blue water, brown hills, green forest, dark squares a town; N for north) → the water by shape (the big area at the edge is the sea; the small shape with land all round it is a lake; the thin line is a river, and rivers run from the hills to the sea) → read it aloud (hills in a long line along the top; the forest between the hills and the lake; both towns beside the river; the table). Rule: A map shows the land from straight above. The legend says what each color and shape stands for, so you can find each thing on the map and say where it sits.

L02 (examples only, the rule induced after): the four parts named with their everyday members → E the river carried the bank's soil away (water on land; erosion recalled) → E the wind pushed the lake into waves (air on water) → E tree roots held the hill's soil (living things on land; roots recalled) → E rain soaked the field and the grass grew (water on living things) → the arrows grid and the table → not kept apart; the hawk and the mouse as the within-one-part sorting sentence → the name. Rule: Earth's four big parts are the land, the water, the air and the living things. Each part acts on the others and changes them. When one part acts on another and changes it, we call that an interaction.

L03 (one frame: "Which part is doing the acting? Which part is being changed? So the X acts on the Y."): the pile of sand — the wind (air) on the sand (land) → the SAME sand with grass — the grass (living things) on the sand (land) → the beaver dam — living things on water → the river mouth — water on land → the flooded field — water on living things → say the acting part first; both things in one part is not an interaction. Rule: To spot the interaction, ask two questions. Which part is doing the acting? Which part is being changed? Then say it: the first part acts on the second.

The rules applied

Misconceptions confronted, by name

The physics catalogue has no Earth-system rows; the sources are the literature named here.

Checker result, every WARN answered

python3 build_tools_check_topic.py grade4/topic26_build/content/G4T26.py → 0 FAIL, 33 WARN.

• S8 × 7 (a beat carries 3–6 sentences): kept. The grade 3-5 anatomy writes a beat as one continuous take of short sentences (the scripts total 148 words each, under the 150 cap); splitting the sentences into more beats would add cue pauses the Peps pipeline reads as silences. Topic 22 carried the same WARNs.
• S36 × 26 unusual words: nakamura (the teacher's name, the brief's row) fine · gopher, prairie (dogs), bobcat, beaver, pelican, elk, moles, seagull — US animals a child knows, each the role-equivalent the rule asks for; fine · boulder(s) (×8) — Grade 3 Topic 26's size strip taught "boulder"; fine · palm (tree) fine · petals, pollen, sprout, dandelion — garden words; fine · reeds (intro only) fine · gust — paired with "breeze" in one stem and glossed "both moving"; fine · salty fine · underneath (one distractor) fine · oval — one why line about the map's lake; swap considered, kept because the legend row says "water" and "oval" is the shape word children use · shallow fine · bumpy, grooves (one why / one stem) fine · hiker fine · splitting fine. Swapped before this run: creek → stream (James: say "river"), ridge → hilltop, slant → "from a hilltop far away", wade → walk, hazy → yellow, sloshes → rises, event(s) → "here" / "cases".
• S33 / S34 / S7 / S28 / S23 / S1 / S5 / S38 — all cleared in the authoring run (legend offered as "a legend" before typing; erosion added to RECALL_BY_MCQ; L01 keys rebalanced; PP-1 / PP-10 / PP-11 reworded; two long idea lines split; two 3-sentence stems shortened; five whys shortened; "Which part?" → "Which part do they belong to?", "The air." → "The air is being changed.").
• The checker's note "could not load G4T21.py: cannot import name 'words' from 'figures'": a side effect of the course-wide S36 word list loading every topic with this topic's content/ first on sys.path (Topic 21's module imports a words helper from ITS figures). Not this topic's fault and not fixed here; it means Topic 21's lexicon words were absent from this run's allowed list (which can only have ADDED S36 WARNs, never hidden any).

python3 grade4/check_g4_articles.py … → 0 FAIL; articles 306 / 373 / 392 words, each WARNed above 300. Kept because each has a subtitle or figure every eight idea lines or fewer (L01: 21 ideas, 5 subtitles, 6 figures; L02: 22 ideas, 6 subtitles, 10 figures; L03: 23 ideas, 6 subtitles, 10 figures) and each stands alone for a child who skips the video; Topic 22's 379-word article was accepted on the same ground. L03 is the longest because the brief named four photos and the frame is run five times.

Bank freshness, re-performed

Scene nouns of every lesson, quiz, attached and practice item: walk, path, bank, lake waves, roots on a hill, rain on a grass field, pile of sand / dune, beach grass, beaver, dam, pond behind a dam, river mouth, flood, crops / corn, hawk, mouse, gopher, tomato garden, dusty road, pine trees leaning, landslide blocking a stream, snow on an apple tree, prairie dogs, dust storm, volcano ash over a town, waves washing sand off a beach, bobcat and rabbit, hill soil sliding onto a road, cattle in a stream, sea cliff, crows, hail on pumpkins, pine pollen, plowed field, hummingbird / cactus / rancher.

Grep over the 53 bank items (stem + options + why): zero hits for pile, dune, beaver, dam, mouth, flood, crops, corn, hawk, mouse, gopher, tomato, dusty, pine, apple, prairie, dust storm, bobcat, cattle, crows, hail, pumpkin, pollen, plowed, hummingbird, rancher, creek, sandstorm. Hits, each explained: path PP-1 (a park map's paths — a map thing, not the river path) · walk PP-2 (a distractor, "how long the walk will take") · beach PP-12 (a sorting item: pelican, palm, fisherman) and PP-48 (a hard chain: the sea onto a beach, then over a field) · cliff PP-13 (sorting rock things) and PP-20 (rocks crush bushes — land on living things; the practice's cliff is water on land) · waves PP-21 (a within-part distractor), PP-32 (an earthquake shakes a lake — land on water), PP-41 (Luna's claim; the key states the lesson's wind-and-waves evidence, as a misconception item must) · cactus PP-22 (rain opens its flowers; the summary's cactus is a sorting item) · ash PP-23 (ash kills plants — land on living things), PP-49 (ash on a lake — land on water); the quiz's ash is land on air · roots PP-29 (moss), PP-43 (Lyla's claim — the lesson's roots evidence as the key, a misconception item), PP-46 (roots split a rock — Topic 20's example, fresh to this topic) · bank PP-42 (Louis's claim about rivers and banks — the lesson's own case as the evidence a misconception item needs) · landslide PP-45 (a distractor word) · grass PP-48 (sea water kills grass — the chain item's second step). Re-scened during the build because the template matched a lesson or quiz item: PP-20 (was wind → sea waves), PP-21 (was cattle trample a bank), PP-23 (was ash fills the air), PP-26 (was a mudslide fills a pond), PP-28 (was a sandstorm buries a road), PP-34 (was hail flattens wheat), PP-35 (beach sand → desert sand), PP-37 (was rain washes a hillside into a creek), PP-46 (was wind ripples + hawk and mouse), PP-53 (was snow snaps oak branches).

Blind-text grep

grep -h '^\[Drawing:' blind/2026-10-02/*.md | grep -E -i 'acts on|carries|moves|changes|wears|interaction' → 0 hits. Every drawn item is a map; its blind text lists the legend rows, the N arrow, which edge the brown shapes and the blue area sit on, the blue line's two ends, the oval's and the patch's positions, the squares' positions and whether they sit next to the blue line, and which drawn thing each letter sits on — data, never a reading. The alt text follows the same form. Note for the blind reader: the map-reading skill is applying the legend to that data, so a reader who knows "brown means hills" can answer from the description; that is the item's skill, not a leak.

Figures (author self-check on the renders; the non-author review-figures pass is owed)

Rendered every key to /tmp/g4t26_figs/*.png with headless Chromium and opened: map_plan, map_headache, side_vs_above, parts_four, arrows_grid, pair_living_land, table_two_questions, table_examples, rule_parts, and all thirteen item / practice / bank maps. Fixed on the render: the hills band ran into the sea on the right (shortened by 50 px); seven item-map layouts had a legend, a town or a river crossing another shape (Q1, Q3, Q5, PR1, PP1–PP7 re-placed); every legend now sits in a corner free of the hills and the sea, every N arrow in free space. Convention stated: the acting part's card is always on the LEFT and the one arrow points RIGHT; the four cards in a row are always WATER · AIR · LAND · LIVING THINGS; an item map's letters sit on the thing they mark. Photo and cartoon placeholders render as the pale box with their note. IMAGE_BRIEFS written for all 11 placeholders (David-only). The picture pass waits for James's sign-off because this record carries questions for him.

Names run

python3 build_tools_names.py Nakamura Louis Luna Lyla → "Nakamura free · Louis free · Luna free · Lyla free", exit 0. No other character or claim-maker is named anywhere in the topic.

Sentence-atomise self-check (summary per lesson; the full 14-row table was run on every paragraph, collapsed to the rows that changed)

Judgement calls

• "rivers carry the water back to the ocean" is Topic 24's rule-card wording, used here as a recalled fact with "the sea" as this topic's working word. If Topic 24 lands with different wording, the four places listed above change to match.
• The bank's T6 items offer FOUR events (one cross-part, three within-part). James banned padded four-option sets for fluency; here every distractor is a documented near miss (an animal acting on an animal; water into water; air past air; rock beside rock), and the move IS the boundary. Flag if he reads it as padding.
• Three living-things-on-land items sit in the bank's T9/T10 (earthworms, moles, moss) plus one in T6 (an alligator digging mud). Each is a different scene kind (mixing, tunnelling, crumbling, digging); the ⟂ list marks earthworms / moles as draw-one.
• The within-part boundary (a hawk and a mouse) is taught in L02 and reused as L03's rule line. One sorting sentence, two lessons; the Grade 3 Topic 41 food-chain idea gives the child the picture.
• "Ash is tiny pieces of rock from the land" sorts volcanic ash as land in three bank items; a strict reading (rock AND glass) is left for Grade 6-8.
• The intro's second question-mark sentence is a statement ("And the sand did not pile itself up into that tall hill. Something piled it there.") so the intro stays at two "?" and still carries the dune gap.
• The S36 word "oval" stays: the alt and the why lines call the lake "the blue oval" because the legend's word is "water" and the lesson's phrase is "the small blue shape with land all round it"; "oval" is the one shape word the item needs.

Owed

• Blind review of blind/2026-10-02/BLIND_BUNDLE_G4T26.md (keys sequestered in KEYS_SEQUESTERED_G4T26.json) by two cold readers; adjudication.
• The non-author review-figures, review-questions and review-lesson passes.
• Topic 24's lexicon check when its content lands (two recalled lines).
• The picture pass (11 placeholders) — after James's sign-off, because this record carries questions for him.
• Videos: handoff/G4T26/videos/batch_G4T26.json + READY.md built and checked, NOT sent (James's word is needed for a Grade 4 batch).
• Nothing committed.

v2 — reviews applied (2 October 2026)

Skill: write-lesson (article lines, the L03 split) → write-video-script (L01 and L03 beats, the L04 script) → write-mcqs (every item change) → write-explanation (fb / why lines) → sentence-atomise (every new sentence) @ 80719f4. Applied in order of authority: BLIND_READ_G4T26_2026-10-02.md, REVIEW_G4T26_2026-10-02.md, FIGURES_REVIEW_G4T26_2026-10-02.md. Nothing committed.

In plain words. The topic is now four lessons on the same walk. The third lesson stops after the two questions have been asked twice on one pile of sand; the beaver, the river mouth and the flooded field, and the "say the acting part first" rule, are a fourth lesson with its own headache (Louis and Lyla say the sand's interaction the two ways round). The videos now speak the two ideas the quizzes key on (the hills' long line; two things in one part is not an interaction). No map's words give away which way the river runs, and no hill sits in any sea.

#### Finding → change

Departure from the reviewer, recorded: PP-47's suggested scene (an Oregon sea cliff's rocks falling into the sea) is PR-10's scene word for word (waves wear away a sea cliff in Oregon). Built instead on the same structure (the part changed in step one acts in step two): heavy rain washes gravel off a Tennessee hillside, then the gravel fills a pond → the land acts on the water.

Questions for James — built as recommended: (1) "interaction" coined, recalled by MCQ; (2) two typed "legend" items, accept lists widened with "map legend"; (3) the boundary sentence stays in L02 and is now spoken in L03's script too.

#### The lessons now

Counts: 4 lessons · 4 scripts + intro (109) + summary (119) · 4 attached + 3 summary questions · 38 quiz items · 15 practice · bank 53 (49 MCQ, 2 typed, 2 multi; EAR4-026 15 · EAR4-080 17 · EAR4-081 21; easy 21 · medium 17 · hard 15; ≥ 5 per atom; tiers rise within each atom; MCQ keys A 13 · B 13 · C 12 · D 11) · 39 figures (28 svg, 8 photo, 3 cartoon).

Key strings. L01 three-option C C A A B B C A, two-option n · L02 three-option A B B A B, two-option y y n n n y · L03 three-option C, four-option A D A B C A D B, two-option n · L04 four-option A D B C C, two-option y n · practice A B C B A B y n C B n B C · attached in video order (L01–L04, S1–S3) B A C B A B C (B 3 of 7).

#### Checks

• check_key_tells.py → KEY TELLS: 0 of 108 MCQs flagged (a: 0, b: 0, c: 0); KEY_TELL_EXEMPT_SETS = [PARTS].
• build_tools_check_topic.py → 0 FAIL, 27 WARN: S8 × 10 beats of 3–8 sentences (kept, as v1: one continuous take under 150 words); S18 L04 quiz 7 items (kept: the bare stage only — L03 carries the scaffold; a simple lesson gets fewer items); S36 × 17 words — new ones spray (PP-21, a child knows the word), zoo (PR-13), rocky (PP-42) fine; the rest as v1. The S36 loader's notes on G4T32 / G4T37 are the course-wide list's side effect, as before.
• check_g4_articles.py → 0 FAIL; articles 306 / 412 / 284 / 272 (L01 and L02 WARN above 300: L02 carries the two sorting lines the blind read asked for, with a subtitle or figure every ≤ 8 lines); scripts 149 / 149 / 150 / 149.
• build_tools_names.py Nakamura Louis Luna Lyla → all free, exit 0.
• check_svg_ids.py → 39 figures, 0 ids, PASS.
• Site built to /tmp/g4t26_v2.html (4 lessons, 15 practice, 53 pp100, 39 figures); every lesson's article and quiz route screenshotted at 1200 and 360 px and looked at: no missing figure; the stacked tables and the legend read at 360 px (legend text ≈ 9 CSS px on the 278 px map — the reviewer's 18-unit spec; the 13 px floor would need a legend wider than the free corners allow, flagged for the figure reviewer).
• Video batch rebuilt (INTRO, L01–L04, SUMMARY; 4,153–5,801 chars, all under 6,000); check_brief.py clean except the INTRO's standing R79 line; grep -ci strand 0. Not sent.
• Every changed figure re-rendered to /tmp/g4t26_figs_v2/*.png and looked at (all 15 maps, parts_four, arrows_grid, pair_air_land, table_two_questions, side_vs_above, table_examples): no hill in any sea; no chip touching a neighbour; no arrow through a chip.
• Fresh bundle blind/2026-10-02-v2/ (106 MCQ, 4 typed, 1 FRQ, 2 multi); grep '^\[Drawing:' | grep -E -i 'acts on|carries|moves|changes|wears|interaction|from the brown|to the blue' → 0 hits over 14 drawing lines.

#### Items changed (v1 numbering, the readers' numbering)

Stem: L02-q1, L02-q7, PR-13, PR-14, PR-15, PP-21, PP-25, PP-28, PP-41, PP-42, PP-43, PP-47, PP-49, PP-50. Options: L02-q2, PP-19, PP-20, PP-21, PP-22, PP-23, PP-24, PP-41, PP-42, PP-43, PP-52, PP-53. Keys: none moved (every key letter unchanged). Model / why / fb: L02-q9, PP-21, PP-42, PP-43, PP-47, PP-49, L03-q5 (snow "frozen water"). Figure: L01-q4 (q_map_2, letters M P R), L01-q6 (q_map_4), L01-q5 (q_map_3 legend), and every map's legend / chip size. Blind text and alt: every lettered map (joining; positions only), q_map_4's alt. Accept lists: L01-q10, PR-14, PP-39, PP-40. Tags: PP-25–30 easy (now PP-16–21 in the file). New items: L03-q1 (deposition recall), L03-q5, L03-q6 (ants; rain on oak leaves), L04-q3, L04-q4, L04-q5 (a pine tree across a stream; sea turtles; Louis's TRUE snow claim), L04's attached question (storm waves and reeds). Moved L03 → L04 unchanged: the dust storm, the ash, Lyla's claim, the transfer.

#### Owed after v2

A second blind read of the v2 bundle (the changed items above); the figure reviewer's look at the 360 px legend; the picture pass (11 placeholders) after James's sign-off; the batch is built and checked, not sent.

v3 — polish (2 October 2026)

Skill: write-mcqs (every item change) → write-explanation (the fb and why lines) → sentence-atomise (every new sentence); review-figures (author self-check on the renders) @ fb37d14. Source: Reader C's full re-read of the v2 bundle (blind/2026-10-02-v2/READER_C.md: 113 items, every key agreed). Nothing committed.

In plain words. Reader C agreed every key; six small things are tidied. The one map item whose description could not carry its answer now says where the river line passes. The ash item says in its own stem that ash is rock. Lyla is now Josie, so no two children's names look alike. One distractor took the key's shape, one more claim is true, and "key" is confirmed on every typed "legend" item. The map legend is now a strip along the bottom of every map, so it reads at phone width.

#### Finding → change

#### Checks

• build_tools_check_topic.py → 0 FAIL, 27 WARN (S8 beats and S36 words as v2; no new WARN).
• check_g4_articles.py → 0 FAIL; articles 307 / 413 / 284 / 272; scripts 149 / 149 / 150 / 149; intro 109; summary 119.
• check_key_tells.py → KEY TELLS: 0 of 108 MCQs flagged (a: 0, b: 0, c: 0).
• check_svg_ids.py → 39 figures, 0 ids, PASS.
• build_tools_names.py Nakamura Louis Luna Josie → all free, exit 0.
• Site built to /tmp/g4t26_p.html (4 lessons, 15 practice, 53 pp100, 39 figures). Legend size: 27 units × 278 / 560 = 13.4 CSS px at a 278 px column; measured on the built page in headless Chrome at its smallest layout (the map at 418 px wide) the legend text is 20.2 px; at 1200 px, 53.9 px.
• Every map re-rendered to /tmp/g4t26_figs_v3/*.png and looked at (map_plan, pp_map_5, q_map_2, pp_map_4, pr_map_1 opened): the strip sits under the land on every map, no drawn thing touches it, pp_map_5's river passes both towns.
• Video batch rebuilt (the L01 script line changed): 6 videos, check_brief.py clean except the INTRO's standing R79 line, grep -ci strand 0. Not sent.
• Fresh bundle blind/2026-10-02-v3/ (106 MCQ, 4 typed, 1 FRQ, 2 multi; 113 held); grep '^\[Drawing:' | grep -E -i 'acts on|carries|moves|changes|wears|interaction|from the brown|to the blue|beside the river|next to the blue line' → 0 hits; "passes both" → 1 (pp_map_5, by design); "Lyla" → 0.

#### Items changed (v2 numbering, Reader C's numbering)

Stem: L04-02, PR-12. Options: L02-02 (option A). Keys: PR-12 no → yes (a rewritten claim, not a flipped key); every other key letter unchanged. fb / why: L02-02 (unchanged), PR-12. Names: L02-10, L03 headache and article, L04 headache, article and script, L04-06, PP-43, the three cartoon briefs and the CAST line (Lyla → Josie). Figure: pp_map_5 (towns moved; blind note); every map's legend (strip). Lesson text: L01's three "box in the corner" lines. Key strings: practice A B C B A B y n C B (frq) y B (text) C; L01–L04 as v2.

#### Owed after v3

The picture pass (11 placeholders) after James's sign-off; the batch is built and checked, not sent; nothing committed.

Skill: course-build → review-lesson (Role A blind key read, two readers; Role C adjudication by the coordinator) @ efd8fba

Topic 26 — How Earth's parts act on one another — blind read, 2 October 2026

Every key agreed by two blind readers (106 items each; MCQ disagreements 0 for both; PP-50 multi C, D and PP-51 A, C matched; the typed "legend" items on the lists; the FRQ model in the key's words). All eight lettered maps match their stems; "legend" and "interaction" are each defined in the stem that names them before any later item uses them. Both readers flag the same two bank items as two-defensible by the topic's own logic. The intro poll is not bundled by design.

Flags carried into the fix pass

Readers' files: blind/2026-10-02/READER_A.md, READER_B.md.

Skill: course-build → review-lesson (Roles B, B2) → review-questions → review-accuracy (non-author pass; filed by the coordinator from the reviewer's hand-back) @ efd8fba

Topic 26 — guidance, questions and accuracy review, 2 October 2026

The topic is sound in its science and its shape — three honest lessons on one walk, a clean four-part vocabulary with no sphere names, keys that all hold — but it is not ready for a cold reader. Three things must change: the videos never speak two ideas the quizzes and bank key on (the within-one-part boundary, and L01's "the hills run in a long line" — the atom's own behaviour); three bank items are quiz scenes with the nouns changed; and every map's alt and blind text says the river runs "from the brown shapes to the blue area", the answer to the three river-direction items. Re-performed: scripts 148 / 148 / 148; intro 109; summary 119; articles 306 / 373 / 392 (longest run between a subtitle or figure 5 lines); bank 53, 15 / 17 / 21 per atom, keys A 13 B 13 C 12 D 11; names clean; the letter lists feed stem and drawing from one list (all seven item-map specs checked). Topic 24's two recalled sentences match (one word apart on the second, defensible). Topic 20's cases recalled, never re-taught. The key-tell checker flags 8 of 101 (PP-20–24 the longest key ×5; PP-41 / 42 / 43 two-clause keys).

The author's three questions, the reviewer's view: (1) coin "interaction" — yes (the register title and Arizona's standard use it; MCQ recall at eleven letters); (2) two typed "legend" items only — yes, add "map legend" to the accept list; (3) the boundary sentence in L02 — keep, but it must also be spoken in L03's script.

Skill: course-build → review-figures (non-author pass; filed by the coordinator from the reviewer's hand-back) @ efd8fba — figures at g3-5-science commit 5ed7cce

Topic 26 — figure review, 2 October 2026

A clean, friendly map: cream sheet, brown hills along one edge, a blue sea with a scalloped coast, one river from hills to sea, a legend that matches every colour and shape, an N arrow. Then on six of the thirteen item maps, a brown hill sitting IN the sea. Page pass: every placed figure renders as alone at desktop width; check_svg_ids.py PASS; thirteen distinct item layouts, no twins; stem letters from the drawer's own lists; pair cards all acting-part-left with one arrow; captions never say "real".

1. Hills in the sea (q_map_1, q_map_4, pp_map_2, pp_map_3, pp_map_4, pp_map_6): _hills_band runs the full edge and the end hill overlaps the sea band. Trim the range on the sea's side.
2. Alt and blind text hand over the direction items: every map says "a blue line FROM the brown shapes TO the blue area" — the key of "which way does the river run?" (q_map_5, pr_map_1, pp_map_6). Write "a blue line joining the brown shapes and the blue area". And the blind text adds ", next to the blue line" only to towns near the river (the key on pp_map_5): positions only.
3. Legend and letters unreadable at phone width: the 560-unit map shows at 278 px on a 360 px phone, legend text ~6 CSS px (the look-up floor is 13); Topic 18's three-column table_two_questions ~5 px cells. Legend text 18, letter chips radius 14 / text 16; the table as two stacked two-column tables.
4. The LAND card's bottom corners spill (square soil and sand rects inside a rounded card) on parts_four, every pair card and the arrows grid. Inset by 1.4 px with matched rx.

Unplaced (3): pair_air_water, pair_water_living, pair_living_water — delete (the arrows grid carries all four L02 interactions; the beaver has its photo).

Minor: q_map_2's legend hides the coast; letter chips touching things on q_map_1, pp_map_1, pp_map_4; the LOUIS map's first town straddles the river; the parts' order differs between the cards and the rule (one order everywhere); side_vs_above's lake slab lies on the grass; the three cartoon briefs need the character pointer so the four people match earlier topics; arrows_grid's WATER → LAND arrow tail leaves the chip, not the card.

Three best: map_plan / map_headache, the six pair cards, arrows_grid. Three weakest: q_map_4 and pp_map_6, q_map_5 / pr_map_1's alt and blind text, table_two_questions on a phone.

Skill: review-lesson @ fb37d14 — Role A, Reader C (cold blind key read), G4T26 v2 bundle, 2 Oct 2026

Takeaway

Every item resolved to one answer for me except PP-22, where the map description places both towns and the lake without saying what the river line passes, so "beside the river" and "beside the lake" cannot be told apart from the text; the drawing itself must settle it. The v1 fault is gone: no map description hands over the river's direction — the direction now comes from the taught rule (a river carries its water to the sea), recalled by L01-01 on the same page. The parts sort is one honest bin each and consistent throughout (ash and dust = land; snow, hail, cloud = water), though L04-02's stem leans on the lesson having said ash is rock, where PP-49 says it in the stem. "Say the acting part first" is applied the same way in every two-part item. Same-part events (hawk and mouse, two crows, deer and bush) are keyed "not an interaction" consistently. The three child names — Luna, Louis, Lyla — all open with L and two end in -a; a nine-year-old skimming could read Luna and Lyla as one child. Term order is sound: "interaction" is coined in L02 and tested there first; erosion, deposition, weathering, precipitation, landslide are recalls, each set first in its quiz.

Items

Adversarial answers (typed items)

Cross-item notes

• Map descriptions give positions only; no description hands over the river's direction. L01-07, PR-05 and PP-23 are answered from the taught rule. Fixed since v1.
• PP-22 is the one map item whose answer the description cannot carry: "beside the river" needs the river line's path, and the text gives only its two ends. Either the drawing shows both towns on the line clearly, or the description should add "the blue line passes the dark squares" (a position, not an answer).
• Parts sort, one bin each, consistent: ash and dust = land (L04-02, PP-29, PP-38, PP-49); snow, hail, cloud, rain = water (L03-06, L03-08, L04-05, PR-07, PP-15, PP-52). Only L04-02 leaves the ash bin to the lesson.
• "Say the acting part first" — every two-part option reads "X acts on Y", every key is the acting part first; PP-52/53 switch to objects (wind/snow, rain/petals), which is fine but a different frame.
• Same-part events keyed "no" everywhere (L02-07, L03-10, PR-08; distractors in PP-26 to PP-30, PP-46 B). Holds only if L02 teaches "two DIFFERENT parts".
• "Is X right?" string across L01-L04 and PR: no, no, no, yes, no, yes, no, no — two yes in eight; the adjudicator may want one more yes.
• Names: Luna, Louis, Lyla — same first letter, same length, two end in -a. Luna and Lyla read as one child at a glance; Louis is also a name children say two ways. Suggest three names with different first letters.
• Terms: "interaction" coined and tested in L02 before L03 uses it in a title; erosion, deposition, weathering, precipitation, landslide, evaporates are recalls, placed first in their quizzes.
• Mild length/shape flags, none decisive: L02-02 (only "and"), PP-02 (longest), PP-46 (longest).

Would not ship as is: PP-22 (answer not carried by the description — drawing check needed); L04-02 (state in the stem, or confirm the lesson states, that ash is rock). Cross-item: rename two of Luna / Louis / Lyla.