Skill: course-build → write-mcqs @ 3a2c39d (v1 @ b0fa825)
Topic 20 — question types in the PP100 bank, one exemplar each (v2, 2 October 2026 — reviews applied)
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 20 bank runs on and prints one exemplar per type in full as it ships in content/G4T20_pp100_bank.py. Item ids are the bank's positions (PP-1 … PP-54) after the v2 reorder (the stone-bench sort moved to the end of the medium tier as EAR4-025; the cliff card moved to the hard tier's second slot as an EAR4-023 carrier item). Every bank item carries type_, its number below. Typed items are starred.
What v2 changed in the bank (blind read + guidance review, 2 Oct 2026). The boundary now binds every item: pieces lying right beside the rock they broke from = weathering; pieces that fell or rolled away from it, down to somewhere new = erosion by Earth's pull. So no weathering item puts the pieces at the foot of a cliff, lighthouse or cave roof any more (PP-1, PP-3, PP-7, PP-17 re-scened on flat ground), and the rockfall card (PP-41) asks "What carried the stones?" instead of the three-way sort. Every type 1 and type 4 option is now two short sentences, so the key is never the one long option; no key bundles a verdict with a "so…" reason; "turns into wind"-style distractors are replaced by real beliefs (broke into dust too small to see; sank into the ground; washed away and is gone for good; the mud was always there). Landing clauses that made erosion items read as deposition are cut (PP-16, PP-23). Six renamed lesson scenes are re-scened (PP-14 Texas fence posts; PP-27 quarry wall; PP-31 ski-lodge parking lot; PP-36 Long Island ridge; PP-50/51 flood water off a farm road). PP-30 no longer narrates the glacier dragging the stones. Accept lists widened (PP-40 gust/gusts/breeze; PP-42 thawed; PP-43 slows down). Concrete is now stone (PP-5 birdbath, PP-47 planter), the simplification "concrete is sand and small stones stuck together, so it breaks like rock" is said once in L02.
What v3 changed in the bank (blind re-read, 2 Oct 2026). No exemplar changed. Two keys were trimmed so no key is the longest option: PP-20's key is now "It pushes the crack wider." (the "takes more room" step moved to the why) and PP-34's is "Flood water carried the mud there. No ice forms in July." PP-9's silliest distractor (cracked rocks come off trucks) is replaced by a real belief, "The rock is too heavy to move. Nothing could have carried it.", and its why adds the correction (ice carries even a heavy rock). Lesson side: L05 now opens with a landslide naming item before the first item whose feedback uses the word; L04 q2 and L07 q6 are re-scened (a flagpole's stone base; a stone picnic table).
One cluster. The topic is one PP100 cluster of six atoms (EAR4-020 → 021 → 022 → 023 → 024 → 025, capstone 025). Items per atom: 9 · 9 · 8 · 10 · 9 · 9. Tiers: 17 easy · 22 medium · 15 hard (3 typed, 1 multi-select, 2 drawn item cards, 9 four-option MCQs). EAR4-020 carries easy only; EAR4-021 and 022 easy and medium; EAR4-023 medium plus two hard (the typed carrier and the rockfall card); EAR4-024 medium and hard; EAR4-025 one medium (the stone-bench sort) and hard. Within each tier the atom tags rise in topic order. The three coined terms (weathering, erosion, deposition) are ten-letter words a grade-4 child cannot reliably spell, so they are recalled by MCQ (RECALL_BY_MCQ), never typed; the typed hard items produce lexicon words that are short and plain: wind, melted, slowed. Key letters: A 11 · B 14 · C 12 · D 13 (typed and multi items excluded; no letter over 28 %).
The bar list (things a generated bank must never use because they break a taught claim or a rule): "gravity" as the carrier or as a force ("Earth's pull" is the carrier; "gravity" names the happening — Grade 3 Topic 3's words); "weather" as a cause of weathering in a stem; any chemical weathering (rust on rock, acid rain, dissolving limestone, and raindrops pitting rock — grades 6-8, EAR-021; running water, waves and waterfalls wear rock, rain does not); landform names (delta, dune as a term, moraine, canyon as a term — Grade 5's; the bank says "a flat fan of sand", "a pile of sand", "a heap of rocks"); the rock cycle beyond dropping; a case where the carrier is a person or a machine (a truck carries gravel is a DISTRACTOR only, never a key); a weathering case whose pieces lie at the foot of a cliff, a tall wall, a lighthouse or a cave roof (the pieces fell — by the boundary that is erosion by Earth's pull); a rockfall asked as the three-way sort (ask "What carried the stones?"); an erosion stem that narrates where the pieces land (that is the deposition half; say "carries it away", stop); "none of these" anywhere except the sort set SORT4, where it is the key in PP-48 (melted rock cooling) and PP-49 (a rock unchanged in a museum case) and never padding; the lessons' own scenes (the hilltop boulder and its pieces, the old stone wall, the flat rock in a field with flakes, the pebbles in a stream, the sidewalk slab and root, the boulder's ice-widened crack, the trail stream's groove, the wind-scoured desert rock, the mountain-top rock with flakes, the grit washed down the slope, the dusty field, the cliff heap on the valley floor, the river's sand, the sand blown along a beach and the dune, the Alaska glacier, the landslide, the sand fan at the lake, the sand pile at a bush, the glacier's melt heap, the river bend's mud, the flood over a field) and the quiz, attached and practice scenes (stone step, desert hill rock, flat field rock, rolling boulder, garden-wall brick, stone wall and pine root, statue crack, dandelion in a parking lot, stone bridge, library steps, barn vines, stone step and root, waterfall ledge, desert rock pits, mountain-top sheets, lake-shore waves, thin desert rock, desert flat rock, canal wall, flood pebbles to a valley field, beach sand across a road, garden-bed soil, river-bank mud, two stream pebbles, beach-path sand, landslide onto a road, farm mud to a stream, sand against a house, Minnesota boulder, canyon wall piece, grains down a river to the sea, Alaska rocks in ice, pebble off a wall, muddy stream over flat land, mountain-stream pebbles rolling, dust behind a wall, glacier melt heap, dune-face sand flying, stream to the sea, Canada ice boulders, fence-post sand pile, stream over a meadow, desert rock flakes, melting snow and path gravel, trees and sand pile, waves and beach pebbles, root and big rock, stream into a bay, stone marker, stone bridge step, stream to a valley town, harbor sand bed, beach sand grains, hillside stone, highway landslide, granite curb, church wall and ice, driveway gravel, island stones, dune fence, mountain stream to a reservoir) never appear as a bank scene; no headache character (Jenna, Jesse, Joel, Miss Ramos) appears in a bank item — claim-makers are "a boy" / "a girl".
The ten types
| # | Question type | Exemplar | Items | Count | Hard end |
|---|---|---|---|---|---|
| 1 | Pick the one case of four that is weathering (or erosion, or wind-carried); every option is two short sentences; the other three are the sibling processes or a person moving rock. | PP-1 | PP-1–3, PP-17, PP-26, PP-33 | 6 | none — easy and medium |
| 2 | Name the described change; fixed set WED4 = weathering / erosion / deposition / a landslide. | PP-4 | PP-4, PP-5, PP-15, PP-16, PP-38 | 5 | none — easy and medium |
| 3 | After weathering, where are the pieces? Four places; the key says "right beside". | PP-6 | PP-6, PP-7 | 2 | none — easy |
| 4 | A claim is fixed as wrong in the stem; pick the sentence that shows it — every option two short sentences of fact, never verdict + reason. | PP-8 | PP-8, PP-9, PP-24, PP-25, PP-34, PP-45, PP-52, PP-53 | 8 | PP-45, PP-52, PP-53 (a half-true claim, or a claim about the order of the three) |
| 5 | A described case → what did the breaking (AGENT sets of four drawn from water / ice / heat and cold / wind / plant roots); or pick the case of four where a named agent did the breaking. | PP-10 | PP-10–14, PP-18, PP-19 | 7 | none — easy and medium |
| 6 | The sort: weathering, erosion, deposition or none of these (SORT4), on a described case or a drawn card. | PP-22 | PP-22, PP-23, PP-37, PP-39, PP-47–51 | 9 | PP-47–51 (a drawn card, two none-of-these cases, one scene asked two ways) |
| 7 | A described case → what carried the pieces; fixed set CARRIER4 = moving water / wind / ice / Earth's pull; or the carrier read off a drawn card. | PP-27 | PP-27–32, PP-41 | 7 | PP-41 (the rockfall card: no carrier is drawn) |
| 8 | What the agent does to the rock, or what made the carrier drop its pieces (DROP4 = It slowed down. / It melted. / It sped up. / It froze.), or a prediction of where the carrier drops its load. | PP-35 | PP-20, PP-21, PP-35, PP-36, PP-44, PP-46 | 6 | PP-44 (predict the one place), PP-46 (reverse the rule) |
| 9 | Type the word: the carrier (wind) or what the carrier did to drop its pieces (melted, slowed). | PP-40* | PP-40, PP-42, PP-43* | 3 | all hard, all typed |
| 10 | Multi-select: every change that is erosion. | PP-54 | PP-54 | 1 | hard |
The exemplars, in full
Type 1 — PP-1 (easy, EAR4-020). Which of these is weathering?
Options: A granite boulder on a golf course splits in two. Both halves stay on the grass. · A truck carries gravel to a building site. The gravel is tipped in a pile. · A river drops mud at its mouth. The mud builds a flat bed. · Wind blows dust across a road. The dust lands in a ditch.
Why: Weathering breaks rock into smaller pieces right where the rock sits. The boulder split in two, and both halves stayed where it sits. So the splitting boulder is weathering.
Type 2 — PP-4 (easy, EAR4-020). A rocky ledge on a hillside splits into flat pieces that stay piled where the ledge was. What is this change called?
Options: weathering · erosion · deposition · a landslide.
Why: The ledge broke into smaller pieces right where it sits. Rock breaking in place is weathering. So this change is weathering.
Type 3 — PP-6 (easy, EAR4-020). A boulder on a prairie breaks apart by weathering over many years. Where are the pieces right after they break off?
Options: in the nearest river · miles away across the prairie · right beside the boulder · at the bottom of the sea.
Why: Weathering breaks rock right where the rock sits. The pieces stay in place when they break off. So the pieces are right beside the boulder.
Type 4 — PP-8 (easy, EAR4-020). A girl says the stones of a garden path can never break because nobody ever hits them. Which sentence shows she is wrong?
Options: Stones only break when a hammer hits them. Nothing else breaks them. · Stones melt in the summer sun. They do not break. · Stones grow bigger every year. They never break. · Stones break apart slowly by themselves. It takes many years.
Why: Bigger rocks slowly break apart by themselves, over many years. Nobody has to hit them. So the stones of the path can break, and the girl is wrong.
Type 5 — PP-10 (easy, EAR4-021). Water fills a crack in a stone patio, and on a freezing night the crack splits wider. What did the breaking?
Options: water · ice · wind · plant roots.
Why: The water in the crack froze into ice on the freezing night. The ice took more room and pushed the crack wider. So the ice did the breaking.
Type 6 — PP-22 (medium, EAR4-022). Hail and heavy rain wash the sand out of a sandbox and across the schoolyard. Weathering, erosion, deposition or none of these?
Options: weathering · erosion · deposition · none of these.
Why: Ask what happened to the rock. The sand was carried away to somewhere new, across the schoolyard. So this is erosion.
Type 7 — PP-27 (medium, EAR4-023). Chunks of rock break off the top of a tall quarry wall and tumble down to the quarry floor, far below. What carried the pieces?
Options: moving water · wind · ice · Earth's pull.
Why: Earth pulls every object down. Earth pulled the chunks down the quarry wall to the floor far below. So Earth's pull carried the pieces.
(The hard end, PP-41: the drawn cliff card — two stones on a ledge, then on the ground at the cliff's foot — asked "What carried the stones?" Hard because no carrier is drawn; the student names Earth's pull from the fall alone.)
Type 8 — PP-35 (medium, EAR4-024). The Mississippi River drops huge amounts of mud where it flows into the Gulf of Mexico. What made the river drop the mud?
Options: It slowed down. · It melted. · It sped up. · It froze.
Why: Where the river meets the Gulf, it slows down. Slow water cannot hold the mud up. So the river dropped the mud because it slowed down.
(The hard end, PP-44: a stream runs fast down a mountain, into a still pool, then out fast again — where does it drop most of its sand? Hard because the student must find the one place along the route where the carrier slows down.)
Type 9 — PP-40\* (hard, EAR4-023, typed). Fine dust from a dirt racetrack ends up on the windows of houses two miles away, on the side the gusts blow toward. Type the one word for what carried the dust.
Accept: wind · the wind · wind. · winds · a wind · the winds · gust · gusts · the gusts · a gust · breeze · a breeze · the breeze. (closed: one carrier of the lexicon's four fits; gust and breeze name the same carrier.) Wrong-term lines: "water" → no water is named; "air" → moving air is called wind.
Why: The dust is dry and fine, and it landed on the side the gusts blow toward. Gusts are wind. So the wind carried the dust.
Hard because: the student produces the carrier's name from the clues alone, with no options in view.
Type 10 — PP-54 (hard, EAR4-025, multi-select). Select every change that is erosion.
Options: A stream carries pebbles from a hill to a valley. · A root splits a rock, and the pieces stay beside it. · Wind blows dry soil from a field onto a road. · A slow river leaves a bed of mud on the floor of a wide valley.
Why: Erosion carries the broken pieces away to somewhere new. The stream carrying pebbles and the wind carrying soil are both carrying. The split rock is weathering, and the dropped mud is deposition. So the set is the stream's pebbles and the wind's soil.
Hard because: the answer is a SET, and the student must sort four changes at once and keep only the carrying.
Design-move inventory (every bank item: the move · the scene kind · the nearest lesson-side instance)
| Item | Move | Scene kind | Nearest lesson-side instance |
|---|---|---|---|
| PP-1–3 | pick the weathering case of four | golf-course boulder / stone lion / barn floor cracking in place | L01 article's stone wall (crumbling in place) — different objects; no quiz item uses this four-case form |
| PP-4, 5 | name the change (WED4) | ledge splits into pieces / stone birdbath cracks in two | L01 quiz q3 (desert rock splits in two) — the quiz asks yes / no, the bank asks the name |
| PP-6, 7 | where are the pieces after weathering | prairie boulder / flat pasture rock | no lesson-side item asks where; L01's rule sentence |
| PP-8, 9 | sentence that corrects a fixed-wrong claim | garden path stones never break / pasture rock was carried in | L01 quiz q9 (rock only breaks when hit — bare yes / no); the bank asks the reason |
| PP-10–14 | case → agent | patio crack and ice / cactus roots / sea waves / Utah rock and blown sand / Texas fence posts, heat and cold | L02 and L03 quizzes — the same move (the atom), every scene new |
| PP-15, 16 | name the change (WED4) — erosion | soil into a culvert / burnt forest floor carried across a valley | L04 quiz's two-option sorts; the bank offers four names |
| PP-17, 26 | pick the erosion case of four | soil down a slope / stream gravel to a campground | L04 attached (stream carries sand to a valley) — different form |
| PP-18, 19 | pick the case of four where a named agent did the breaking | ice in a crack on a cold night / tree roots and a stone fountain | L02 / L03 quizzes — reversed direction (agent → case) |
| PP-20, 21 | what the agent does to the rock | ice in a crack / Nevada hillside heat and cold | L02 / L03 articles' mechanism lines; no quiz item asks the mechanism |
| PP-22, 23 | the sort (SORT4) — erosion | sandbox sand across a schoolyard / hilltop-lot soil carried off | L04 quiz two-option sorts; the bank adds deposition and none of these |
| PP-24, 25 | sentence that corrects a fixed-wrong claim | gravel beside a bridge "disappeared" / infield dirt "being broken" | L04 quiz q9–q10 (bare yes / no claims); the bank asks the reason |
| PP-27–32 | case → carrier (CARRIER4) | quarry wall to the floor / Colorado River gravel / volleyball-court sand at bleachers / scratched valley floor in Montana / soaked hillside into a ski-lodge parking lot / backyard soil in a gutter | L05 quiz — the same move (the atom), every scene new |
| PP-33 | pick the wind-carried case of four | building-site dirt across a highway | L05 quiz (sand against a house) — different form |
| PP-34 | sentence that corrects a fixed-wrong claim | mud on a flooded street "carried by ice" in July | L05 headache (river "carried" the cliff rocks) — the belief differs (ice, not water) and the scene is new |
| PP-35, 36 | what made the carrier drop (DROP4) | Mississippi mud at the Gulf / Long Island ridge from a glacier | L06 quiz (stream at the sea; Canada ice boulders; fence sand) — same move, new scenes |
| PP-37 | the sort (SORT4) — deposition | mud behind a beaver dam | L07 quiz q1 (stream over a meadow) — new scene |
| PP-38 | name the change (WED4) — deposition | wind-carried sand settles on a marsh | L06 quiz (term recognition from a definition); the bank names it from a case |
| PP-39 | the sort (SORT4) — weathering, the near miss | stone bench cracks, halves stay | L07's boundary case (pieces beside the boulder) — new object, retagged EAR4-025 |
| PP-40* | type the carrier | racetrack dust on windows | L05 quiz (sand against a house) — the bank item has no options |
| PP-41 | the carrier read off a drawn card | two stones on a cliff ledge → the cliff's foot | L05 headache's rockfall SCENE KIND, a fresh drawing (cliff at the right, two stones, lower ledge); asks the carrier, never the sort |
| PP-42, 43 | type what the carrier did | iceberg stones on the sea floor / stream sand at a swamp | L06 quiz (three-option MCQ); the bank item has no options |
| PP-44 | predict where the carrier drops | fast stream → still pool → fast stream | L06 article's rule; no lesson-side prediction item |
| PP-45 | half-true claim: the mud "is still being carried" | mud at a river's mouth | L06 headache (Joel: the river is still carrying this sand) — the SAME belief on a new scene (mud, a mouth, no lake); ⟂ with L06, drawn only after L06 is passed |
| PP-46 | reverse the rule: which change makes the carrier keep its load | slow river after heavy rain | no lesson-side item |
| PP-47 | the sort on a drawn card | stone planter box cracks | L07 quiz transfer (stone marker card) — a new drawing |
| PP-48, 49 | the sort — none of these | lava cooling into rock / museum rock unchanged | no lesson-side item; Topic 18's igneous sentence for PP-48 |
| PP-50, 51 | the sort on one scene asked two ways | flood water, farm road, flat field | L07 article's sequence line; ⟂ each other (one per test) |
| PP-52, 53 | sentence that corrects a fixed-wrong claim | river-mouth sand "never eroded" / gatepost chips "show erosion" | L07 quiz q8 and q10 (bare yes / no claims); the bank asks the reason |
| PP-54 | multi-select: the erosion set | stream pebbles / split rock / wind soil / river mud | no lesson-side multi-select |
⟂ draw constraints (never in one drawn test together)
- PP-50 (stones coming to rest on the field: deposition) ⟂ PP-51 (stones carried off the road: erosion) — one scene asked two ways; each prints the other's setting.
- PP-48 (lava cools: none of these) ⟂ PP-49 (museum rock: none of these) — two "none of these" keys in one test would teach the option.
- PP-40* (type wind) ⟂ PP-33 (pick the wind-carried case) ⟂ PP-29 (volleyball sand: wind) — three wind-carrier keys; draw at most two per test.
- PP-42* (type melted) ⟂ PP-36 (Long Island ridge: it melted) ⟂ PP-46's option "The river freezes over." — PP-36's key prints PP-42's answer; one per test.
- PP-43* (type slowed) ⟂ PP-35 (Mississippi: it slowed down) ⟂ PP-44 (where the stream drops its sand) — each states or produces "slowed down"; draw at most two per test.
- PP-45 (mud at a river's mouth is no longer carried) ⟂ PP-52 (river-mouth sand did go through erosion) — two river-mouth claims; one per test.
- Rule-stating and give-away pairs (blind read, 2 Oct 2026): PP-6 ⟂ PP-7 ⟂ PP-9 ⟂ PP-53 ⟂ PP-47 — five "pieces right beside it" keys; each states the boundary the others test; draw at most two per test. PP-25 (the dirt was carried, not broken) ⟂ PP-26 (pick the erosion case) ⟂ PP-23 (hilltop-lot soil) ⟂ PP-16 (burnt forest floor) — the first states the rule the other three apply; draw at most two per test.
- PP-20 (ice pushes the crack wider) ⟂ PP-10 (patio crack: ice) ⟂ PP-18 (pick the ice case) — PP-20's key is PP-10's and PP-18's reasoning; one per test.
- PP-21 (heat and cold: swell and shrink) ⟂ PP-14 (Texas posts: heat and cold) — PP-21's key is PP-14's reasoning; one per test.
- PP-41 (rockfall card: Earth's pull) ⟂ PP-27 (quarry wall: Earth's pull) ⟂ PP-31 (ski-lodge landslide: Earth's pull) — three Earth's-pull keys; draw at most two per test.