Skill: course-build → write-mcqs @ b0fa825
Topic 16 — question types in the PP100 bank, one exemplar each (2 October 2026; v2 the same evening, after the blind read and the guidance review; v3 polish the same night, after the re-read; v4 polish after the v3 re-read: PP-53 rebuilt, PP-44's key lengthened)
James reviews a bank as its question TYPES first, one exemplar each (vault: 50 Decisions/A bank is reviewed as its question types first, one exemplar each.md). This sheet lists the ten types the Grade 4 Topic 16 bank runs on and prints one exemplar per type in full as it ships in content/G4T16_pp100_bank.py. Item ids are the bank's positions (PP-1 … PP-53). Every bank item carries type_, its number below. Typed items are starred. Under the standing brief (James, 2 Oct 2026: "go straight to the lessons") the bank is built in the same pass as the lessons; this sheet is the first thing James reads, and any type he strikes is removed with its items.
One cluster. The topic is one PP100 cluster of three atoms (MAT4-024 → 060 → 061, capstone 061). Items per atom: 16 · 19 · 18. Tiers: 18 easy · 20 medium · 15 hard (5 typed, 1 multi-select, 9 four-option MCQs). MAT4-024 carries easy and medium only (12 · 4); MAT4-061 carries medium and hard only (6 · 12). No term is coined in this topic, so the hard tier's typed items produce the two new materials the lessons NAME (rust, ash) and three of the lexicon's clue words (bubbles, color, smell); the fourth clue, a new kind of solid, is a phrase, so it is asked as a hard CLUE4 MCQ (PP-53, v4). v2 (2 Oct, evening): the five "shows she is wrong" items the guidance review named (PP-21, 32, 39, 44, 45) are rebuilt as positive what-is-it items with four accounts a child gives, the key never the longest option, and now sit under type 3; type 6 keeps PP-30, 31 and 41 (distractors real, keys trimmed to the distractors' length); PP-3 and PP-6 no longer print "water vapor"; PP-37 offers the fourth clue (a new kind of solid, the CLUE4 set) in place of a second cut-fruit colour item; PP-53 types the fourth clue (solid) in place of a second rust item; PP-33 and PP-42 are re-scened off the lesson quiz's copper roof and shovel; PP-23 spoils grapes, not mouldy yogurt (mould is alive); PP-24 asks about the wax turning liquid on a warm candle. Keys A 12 · B 11 · C 12 · D 11 of 46. v4 (2 Oct, after the v3 re-read): PP-53's typed stem was circular (it said "a new material formed" and asked for "a new kind of ___", so "material" was a fair answer) — it is now a hard four-option MCQ on the CLUE4 set, keyed a new kind of solid, on a plaster cast setting on a girl's arm (white to white, no smell, no bubbles; the plaster's warmth, which cools again, is the changes-back decoy); the fired-clay scene is dropped because L02's rolled clay sits on the bar list below. PP-44's one-word key "rust" is now "rust, a new material", the distractors' shape. Keys A 12 · B 11 · C 12 · D 12 of 47.
The bar list (things a generated bank must never use because they break a taught claim or a rule): the words "physical", "chemical", "irreversible" and "reversible" (grades 6-8's; say "it will not change back"); "gravity"; a candle BURNING as a sort case (the wax melts AND the wick burns — two changes in one scene; dripping wax alone is fine); a steel object as the thing that rusts without "iron" or "steel" named (the course says rust forms on iron); "steam" for the white cloud (Grade 3 Topic 21 says the cloud is liquid drops; the gas is "water vapor"); any case that needs the melting point of a substance other than water (a crayon on a dashboard is James's own example of an everyday uncertainty — the one crayon here melts "in a hot car" as a distractor only, flagged for his word); no option that says melting "makes a new material" as a KEY; no option calling water vapor "not water"; the lessons' own scenes (the frozen water bottle, the lunch bag, the cooler, the match and campfire, the nail on the picnic table, the cake, the paper strips, the sugar in water, the banana, the fizzing tablet, the frozen puddle, the frosted window) and the quiz, attached and practice scenes (skating rink, dog's bowl, dumplings, snow cone, swimsuit, hose and tomatoes, humidifier, chocolate bar in a hot car, dry leaves, bike chain, snowman, carrot, fried egg, toast, salt in soup, clay, charcoal grill, garden rake, lemon, copper roof, vinegar and baking soda, butter, frost on grass, marshmallow, pancake, iron gate, iron shovel, fireplace log, sour milk, hail, cut apple, steel chain in a yard, snow on a roof, sealed bag of ice, rock, bag of ice on a knee, shower mirror, fence post, pumpkin on a porch, honey in tea, ice pop, corn stalks, steel wheelbarrow, sticks in a wood stove) never appear as a bank scene; no headache character (Frankie, Gabriel, Gavin, Miss Mendez) appears in a bank item — claim-makers are "a boy" / "a girl".
The ten types
| # | Question type | Exemplar | Items | Count | Hard end |
|---|---|---|---|---|---|
| 1 | A use of water → the state it relies on; fixed set solid water / liquid water / water vapor / a material that is not water. | PP-1 | PP-1–7, PP-22 | 8 | none — easy and medium |
| 2 | Pick the one use (of four) that needs a named state. | PP-8 | PP-8–10 | 3 | none — easy |
| 3 | After a change, what is the thing now (the ice, the water in the air, the melted ice cream, the flakes); four accounts a child gives, the key never the longest. | PP-11 | PP-11, PP-12, PP-19, PP-20, PP-21, PP-32, PP-39, PP-44, PP-45 | 9 | PP-39, PP-44, PP-45 (a big change in look, or the rain test, before the account) |
| 4 | Which kind of change is this? Fixed four-way set: a new material · the same material in a new state · in a new shape · mixed into something. | PP-13 | PP-13–17, PP-23–27 | 10 | none — easy and medium |
| 5 | Pick the one change of four that makes a new material (or keeps the same material). | PP-18 | PP-18, PP-28, PP-29, PP-40 | 4 | PP-40 (four cases in one scene, one key) |
| 6 | A claim is fixed as wrong in the stem; pick the sentence that shows it (reason form, never verdict + reason; every distractor a real account; the key no longer than the distractors). | PP-30 | PP-30, PP-31, PP-41 | 3 | PP-41 (a half-true claim: the salts cannot be seen) |
| 7 | What is the clue that a new material formed? Two fixed sets: CLUE4 (a new color / a new smell / bubbles / a new kind of solid) on PP-35, PP-37 and PP-53; CLUE4_NO (a new color / a new smell / bubbles / There is no clue.) on PP-33, 34, 36, 38, so "There is no clue." is offered four times and keyed twice. | PP-33 | PP-33–38, PP-53 | 7 | PP-53 (a changes-back decoy in the scene, then the fourth clue) |
| 8 | Which observation (of four true ones) shows a new material formed? | PP-42 | PP-42, PP-43, PP-46 | 3 | all hard |
| 9 | Type the word: the new material's name from its properties (rust, ash), or the kind of clue (bubbles, color, smell). | PP-48* | PP-48–52 | 5 | all hard, all typed |
| 10 | Multi-select: every observation that is a clue. | PP-47 | PP-47 | 1 | hard |
The exemplars, in full
Type 1 — PP-1 (easy, MAT4-024). An ice sculpture of a swan stands on a table at a winter fair. Which state of water is the swan made of?
Options: solid water · liquid water · water vapor · a material that is not water.
Why: Ice is water as a solid. The swan is carved from ice. So the swan is made of solid water.
Type 2 — PP-8 (easy, MAT4-024). Which of these needs solid water?
Options: filling a swimming pool · keeping fish fresh on a bed of ice · warming the air of a steam room · rinsing a paintbrush.
Why: Ice is water as a solid. Fish stay fresh on a bed of ice because solid water keeps things cold. So keeping fish fresh on ice needs solid water.
Type 3 — PP-11 (easy, MAT4-024). A lake freezes over in January. What is the sheet of ice on the lake?
Options: water, in a new state · a new material · water mixed with a new material · nothing: the water is gone.
Why: Ice is water, frozen. Freezing changes the state, not the stuff. So the sheet of ice is water, in a new state.
Type 4 — PP-13 (easy, MAT4-060). A glass jar falls and breaks into many pieces. Which kind of change is this?
Options: a new material · the same material, in a new state · the same material, in a new shape · the same material, mixed into something.
Why: Every piece is still glass. The shape changed, and the material did not. So this change keeps the same material, in a new shape.
Type 5 — PP-18 (easy, MAT4-060). Which of these changes makes a new material?
Options: a wax crayon melts in a hot car · a board is sawed in half · bread dough bakes into a loaf · drink powder dissolves in a jug of water.
Why: Melted wax is still wax, sawed wood is still wood, and dissolved drink powder is still drink powder. Baked dough turns into a loaf, a new kind of solid that will not turn back into dough. So baking the dough makes a new material.
Type 3, the v2 shape — PP-44 (hard, MAT4-061; v3 re-cased off the lesson's nail, boy and rub; v4 key lengthened to the distractors' shape). An iron bench in a park turns red-brown and flaky over the years. A week of rain pours over the bench, and the red-brown stays. What is the red-brown?
Options: dust the wind blew onto it · mud that splashed onto it · the iron, in a new state · rust, a new material.
Why: Rain washes dust and mud off the iron. The red-brown stays through the rain, so it is a new color that will not change back. A new state would be a liquid or a gas, and the bench is still solid. So the red-brown is rust, a new material.
Hard because: the rain is the wiper (dust and mud wash off; a new color stays), and the student must then separate a new material from a new state before naming the red-brown.
Type 6 — PP-30 (medium, MAT4-060). A girl says the wood of a burnt stick has disappeared into nothing. Which sentence shows she is wrong?
Options: The wood melted into the ground. · The wood turned into ash and smoke. · The wood is hiding under the ash. · The ash is the wood, with a new color.
Why: The wood did not disappear. It turned into ash and smoke, two new materials. Ash is not wood with a new color: ash is a new material. So the wood is still here, as ash and smoke. (v3: the fourth option was "The wood turned into water.", an option no child picked; the new one is the same-material-new-color belief, which a child does pick.)
Type 7 — PP-33 (medium, MAT4-061). A silver fork kept in a drawer for years turns dark and dull, and the dark stays when the fork is rinsed. What is the clue that a new material formed?
Options: a new color · a new smell · bubbles · There is no clue.
Why: The fork's color changed from shiny silver to dark. The dark will not change back. So the new color is the clue that a new material formed.
Type 7, the CLUE4 set — PP-37 (medium, MAT4-061). Gray cement powder is mixed with water, and by the next day it has set into hard, gray concrete that will not turn back into powder. What is the clue that a new material formed?
Options: a new color · a new smell · bubbles · a new kind of solid.
Why: The powder's color did not change, and no smell or bubbles came. Soft powder set into hard concrete, a new kind of solid that will not change back. So the new kind of solid is the clue that a new material formed.
Type 7, the hard end — PP-53 (hard, MAT4-061; v4, was a typed item). A doctor wraps a girl's broken arm in a bandage soaked in wet, white plaster. The plaster feels warm for a few minutes, then cools. Within an hour the plaster is a hard white cast that will not turn back into wet plaster. Which clue shows a new material formed?
Options: a new color · a new smell · bubbles · a new kind of solid.
Why: The warm plaster cools again, so the warmth is not a clue. The plaster stayed white, with no smell and no bubbles. Wet plaster set into a hard cast, a new kind of solid that will not change back. So the new kind of solid is the clue.
Hard because: the plaster's warmth is a true change that changes back, so the student must rule it out as a clue, then reject the three clues children name first (no new color, no smell, no bubbles) and recognise the fourth, the one the lesson names last.
Type 8 — PP-42 (hard, MAT4-061). A sliced pear sits on a plate for an hour. Which thing seen on the slices then shows that a new material formed?
Options: The cut sides have turned brown, and the brown stays. · The slices are warmer than when they came out of the fridge. · A little juice has run out onto the plate. · The slices have been moved into a neat row.
Why: The clue is a changed property that will not change back. Warmer slices cool again, run-out juice is still pear juice, and a row is only a new place. A brown that stays is a new color that will not change back, so it shows that a new material formed.
Hard because: four observations are all true of the slices, and the student must pick the one that is a changed property that will not change back. (v2: re-scened off L03-q12's shovel; the key is no longer the longest option.)
Type 9 — PP-48\* (hard, MAT4-061, typed). An iron fence left wet for a year turns red-brown and flaky, and the color stays when it is rubbed. Type the name of the new material on the fence.
Accept: rust · the rust · rusts · rust. · iron rust · rusting · rusty · rusted · rusted iron (v2, from the blind readers' notes). (closed: the stem describes one named material, rust, which the lessons name on their cards.)
Why: The fence's color changed to red-brown, and the new color will not change back. The red-brown, flaky material is rust. Rust is a new material that formed on the iron.
Hard because: the student produces the material's name from its properties, by recall.
Type 10 — PP-47 (hard, MAT4-061, multi-select). A tray of pale cookie dough bakes in a hot oven. Select every observation that would be a clue that a new material formed.
Options: The cookies turn golden brown. · The tray is hot to touch. · A baked smell fills the kitchen. · Each cookie spread out wider than its ball of dough.
Why: The clue is a changed property that will not change back: a new color, a new smell, bubbles, or a new kind of solid. The golden brown color and the baked smell are clues. A hot tray and a wider shape are not. So the set is the new color and the new smell.
Hard because: the answer is a SET, and picking it needs every clue the lesson names at once, against two changes that change back.
⟂ draw constraints (never in one drawn test together) — v2, with the blind readers' additions
- PP-42 (sliced pear turns brown: the one observation) ⟂ PP-51 (cut avocado turns brown: type "color") — the same colour change on two cut fruits; one per test.
- PP-48 (type rust, iron fence) ⟂ PP-17 (steel door turns red-brown: a new material) ⟂ PP-44 (the red-brown on an iron bench: what is it? rust) — each prints or produces rust's red-brown; draw at most two per test. PP-44 ⟂ PP-42 is withdrawn (PP-42 is a pear now).
- PP-31 (salt in the sea has disappeared) ⟂ PP-41 (bath salts have turned into bath water) — one dissolved-salt claim per test.
- PP-49 (type ash) ⟂ PP-15 (fence boards burn to ash) ⟂ PP-30 (burnt stick: ash and smoke) — PP-15's and PP-30's stems and keys print "ash"; PP-49 produces the word (readers A and B).
- PP-50 (type bubbles), PP-51 (type color), PP-52 (type smell) ⟂ every clue MCQ (PP-33–38, PP-53) — the option sets print the typed words (reader A); draw a typed clue item or a clue MCQ, not both.
- PP-36 (water freezes then melts back: no clue) ⟂ PP-45 (pond ice melts back: the ice was water all along) ⟂ PP-11 (lake ice is water in a new state) ⟂ PP-21 (bird-bath ice is the bath's water, frozen) — four faces of one fact; at most two per test. PP-21 ⟂ PP-39 (snow fort's water is the same stuff as the snow) for the same reason (reader A).
- PP-20 (dried footprints' water is in the air) ⟂ PP-12 (chalk drawing dries: the water is in the air) ⟂ PP-19 (dew's water was water vapor) — one account of water in the air per test (reader A).
- PP-3 (a sauna's air: water vapor) ⟂ PP-9 (warming the air of a steam room needs water vapor) — the hot damp room twice.
- PP-33 (silver fork turns dark) ⟂ PP-28 (copper penny turns dull brown, a distractor) — a metal's new colour twice.
- PP-37 (cement sets into concrete: a new kind of solid) ⟂ PP-53 (wet plaster sets into a cast: a new kind of solid, v4) — the fourth clue keyed twice; one per test.
Design-move inventory (the bank's lines; the lesson side is in BUILD_RECORD_G4T16.md)
Columns: id · move · scene kind · nearest earlier item. "New" = no earlier item shares the move AND the scene kind.
| id | move | scene kind | nearest earlier |
|---|---|---|---|
| PP-1 | use → state (solid) | a carved ice sculpture at a fair | L01-q2 (skating rink) — same move, new scene kind (a carved object) |
| PP-2 | use → state (liquid) | a fish bowl | L01-q3 (dog's bowl) — same move, water a pet lives in, not drinks |
| PP-3 | use → state (gas) | a sauna: water on hot stones goes into the air | L01-q8 (humidifier) — same move, a room not a device; v2 stem no longer prints "water vapor" |
| PP-4 | use → state (liquid) | a car wash | L01-q7 (hose) — same move, a machine's spray |
| PP-5 | use → state (solid) | igloo blocks | PP-1 — same move, ice as building blocks |
| PP-6 | use → state (gas) | tamales on a rack above boiling water in a tall pot | L01-q4 (dumplings in a basket) — the lexicon's one gas job (water vapor cooks food) asked on a different food and pot; fluency repetition of the job sentence, recorded; v2 stem no longer prints "water vapor" |
| PP-7 | use → state (liquid) | a watering can | L01-q7 (hose) — same move, hand-poured |
| PP-8–10 | state → the one use of four | no scene: four uses listed | new move (the reverse of type 1) |
| PP-11 | what the ice is after freezing | a lake in January | L01-q1 (melted frost) — the freezing face |
| PP-12 | where the dried water is | a chalk drawing on a sidewalk | L01-q10 (water dried off a bench, claim) — the account form |
| PP-13 | sort four-way: new shape | a broken jar | L02-q5 (chopped carrot) — same class, a breakage not a cut |
| PP-14 | sort four-way: new state | cheese melts on a burger | L02-q1 (chocolate melts) — same class, a food melting in cooking |
| PP-15 | sort four-way: new material (burning) | fence boards on a burn pile | L02-V (fireplace log) — same class, outdoors |
| PP-16 | sort four-way: mixed in | cocoa in milk | L02-q8 (salt in soup) — same class, a powder |
| PP-17 | sort four-way: new material (rusting) | a truck's steel door | L02-q3 (bike chain) — same class, a large steel part |
| PP-18 | pick the one new-material change of four | four kitchen and workshop changes | new move |
| PP-19 | what dew's water was before | a spider web at dawn | PR-5 (shower mirror) — the outdoor face of condensing |
| PP-20 | claim fixed wrong: dried water is gone | wet footprints on a pool deck | L01-q10 (bare yes / no) — the reason form |
| PP-21 | what the ice is: four accounts | ice on a bird bath on a cold night | PP-11 (lake ice) — the same fact on a small outdoor water; v2 (was: a claim about ice in a drink, L01-q9's scene) |
| PP-22 | use → state, two states in one scene | a bag of ice chilling a watermelon | PR-4 (ice on a knee) — same move, the melt named in the stem |
| PP-23 | sort four-way: new material (spoiling) | grapes forgotten in a school desk turn soft, brown and sour | PR-7 (pumpkin rots) — same class, a fruit indoors; v2 (was mouldy yogurt: mould is alive) |
| PP-24 | sort four-way: new state (melting) | the wax at the top of a warm candle turns to liquid | L03-q4 (butter melts, sets) — the sort form; v2 asks about the one change (the wax turning liquid), so "a new shape" is no longer a second read |
| PP-25 | sort four-way: mixed in | a lollipop in the mouth | PP-16 — same class, dissolving in the mouth |
| PP-26 | sort four-way: new shape | foil crumpled | PP-13 — same class, a bend not a break |
| PP-27 | sort four-way: new material (burning) | a firework | PP-15 — same class, no ash left to see |
| PP-28 | pick the one same-material change of four | four color changes and one melt | PP-18 — the reverse ask |
| PP-29 | pick the one new-material change of four | four winter-kitchen cases | PP-18 — new scenes; draw one per test with PP-18 and PP-40 |
| PP-30 | claim fixed wrong: burnt wood disappeared | a burnt stick | L02-q11 (charcoal, bare yes / no) — the reason form |
| PP-31 | claim fixed wrong: dissolved salt disappeared | the sea | L02-q12 (salt in a glass, bare yes / no) — the reason form |
| PP-32 | what the melted thing is: four accounts | a scoop of ice cream melts in a bowl | L02-q1 (chocolate, recall) — the account form; v2 (was a claim) |
| PP-33 | the clue: a new color | a silver fork turns dark in a drawer | L03-q2 (copper roof) — same move on a different metal indoors; v2 (was a bronze statue turning green: the roof's own change) |
| PP-34 | the clue: a new smell | a fish left out | L03-V (sour milk) — same move, a fish |
| PP-35 | the clue: bubbles | a nurse's clear liquid on a scrape | L03-q3 (vinegar and baking soda) — same move, a first-aid scene |
| PP-36 | the clue: none (froze and thawed) | a glass of water in a freezer | L03-q4 (butter melts and sets) — same move, water |
| PP-37 | the clue: a new kind of solid (CLUE4 set) | cement powder and water set into concrete | new — the fourth clue, with no colour, smell or bubble change in the scene; v2 (was a sliced pear, PP-51's move) |
| PP-38 | the clue: none (nothing changed) | a gold ring | new (no change at all) |
| PP-39 | what the melted thing is: four accounts | a snow fort melts into slush and water | PR-9 (ice pop, bare yes / no) — the account form; v2 (was a claim) |
| PP-40 | pick the one new-material change of four | four winter-morning cases | PP-29 sibling |
| PP-41 | claim fixed wrong: dissolved salts became water | bath salts | PP-31 — same move; draw one per test |
| PP-42 | the one observation that is a clue | a sliced pear on a plate | PP-43 (oatmeal) — same move, a cut fruit; v2 (was iron railings: L03-q12's shovel line for line) |
| PP-43 | the one observation that is a clue | a pot of oatmeal | PP-42 — same move, a cooking scene, state changes as decoys |
| PP-44 | what the red-brown is: four accounts after a week of rain (the rain is the wiper) | an iron park bench | L03-q9 (iron gate mud, bare yes / no) — the account form; v2 (was a claim); v3 (was a bicycle rubbed by a boy: the lesson's nail scene, reader C) |
| PP-45 | what the melting back shows: four accounts | a frozen pond melts in spring | L03-q11 (frost on a window, bare yes / no) — the account form; v2 (was a claim) |
| PP-46 | pick the one clue among two changes to one thing | a bagel frozen, thawed, burnt | new (one object, two kinds of change) |
| PP-47 | multi-select: the set of clues | cookie dough baking | new |
| PP-48* | type rust from its properties | an iron fence | PR-12 (iron in the rain) — same move, new scene |
| PP-49* | type ash from its properties | a pizza oven | PR-13 (wood stove) — same move, new scene |
| PP-50* | type the clue: bubbles | baking powder in hot water | new (production) |
| PP-51* | type the kind of clue: color | a cut avocado | new (production) |
| PP-52* | type the kind of clue: smell | sour cream ("a sour stink": the stem no longer prints "smell") | new (production) |
| PP-53 | the clue: a new kind of solid (CLUE4 set), with a changes-back decoy (the plaster warms, then cools) | a plaster cast setting on a girl's broken arm | PP-37 (cement sets into concrete) — same move, a medical scene not a building job; the warmth decoy is new; v4 (was typed "solid" on fired clay, which L02's rolled clay bars; v2 was a second rust item) |