Skill: course-build → write-mcqs (PP100 bank, type sheet first) → write-explanation @ b0fa825
Topic 19 — The three rock families — the PP100's ten question types, with their exemplars
v2 (2 October 2026, the blind read and the guidance review applied). The family-sort items are THREE-option (James's Q1 built as the reviewer recommended: "a mineral" struck — a category error no child can act on, never a key); eleven items re-scened (PP-01, 02, 11, 12, 19, 23, 33, 34, 35, 36, 37); PP-37's fourth option replaced; PP-27's card gains "hard", "smooth" and "all lined up the same way"; PP-44 accepts "igneous rocks"; PP-49 carries a wrong-term line for "igneous"; the ⟂ list below is the blind readers'. The topic module declares the three-option set in PP100_THREE_OPTION_SETS; the checker's S11 accepts it and prints a WARN naming the count, so James's call stays visible.
Read this first. The bank (content/G4T19_pp100_bank.py) has 52 items: 33 four-option MCQs, 14 three-option family sorts, 3 typed items, 2 multi-selects. One PP100 cluster (the architecture's Topic 19, capstone EAR4-005). Every item carries exactly one atom and a depth tag; the tiers are easy 16 / medium 22 / hard 14, and the depth rises with the atom's place in the topic (EAR4-011 easy and medium only; EAR4-005 and EAR4-006 carry eleven of the fourteen hard items). Keys on the 33 four-option MCQs A 8 · B 10 · C 7 · D 8; on the 14 three-option sorts A 4 · B 5 · C 5. Typed keys: slate (PP-40), igneous (PP-44), granite (PP-49). The bank's hard tier mixes typed items with chained or near-miss MCQs, as the Grade 4 brief allows ("hard items where typing produces … or a well-made MCQ").
Fourth option on the family sort — struck (v2). v1 carried "mineral" as a fourth option (Topic 17's sister word; Happs 1982); the guidance reviewer ruled it a category error no child can act on, never a key, and James's Q1 was built as recommended: the fourteen family sorts are three-option. Items that need no family set still use four rock descriptions, four rock names, four places or four events.
Bar list for a generated bank. Never name shale as a rock that holds water (its tiny spaces are too small for water to move, so the course leaves it out of L04); never call marble a rock with tiny spaces; never name a Pennsylvania roof, a Vermont quarry, a courthouse, a rock box, a dropper, a sponge or a glass block (the lessons' own scenes); never type "metamorphic" (eleven letters, RECALL_BY_MCQ); never use "crystal" (Topic 17's word is grain).
The ten types
| # | Type (stem shape · option kind) | Atom(s) | Tier | Items |
|---|---|---|---|---|
| 1 | A drawn look box: "Which look / which family / which rock could this be?" · the four looks, the four families, or four rock names | 011, 005 | easy–medium | 7 |
| 2 | A described rock (a clue card or one sentence): "Which family is it?" · the four families | 005 | easy–hard | 8 |
| 3 | "Which of these four rocks is <family>?" · four one-line rock descriptions (or two lettered rocks + both / neither) | 011, 005 | medium | 5 |
| 4 | A named rock → its family, or a before rock → its after rock (and back); a look feature → what it lets the rock do · four rock names, the four families, or four events | 011, 012 | easy–hard | 9 |
| 5 | "Which clue tells these two rocks apart?"; the sort run backwards (family → the look it must have) · four clue sentences or four looks | 011, 005 | medium–hard | 5 |
| 6 | The mechanism: where, which two things, what the rock on top does, what really happens · four places / pairs / events | 012 | easy–hard | 6 |
| 7 | A hot rock's path (melts and cools / stays solid and is squeezed) → its family · the four families | 012 | medium | 2 |
| 8 | Tiny spaces: which rock has them, where oil or gas sits, what a drop or a table shows, a real outcome's reason · four rocks / places / statements | 006 | easy–hard | 10 |
| 9 | Typed: the rock's or the family's name from its clues (slate, igneous, granite) | 012, 005, 006 | hard | 3 |
| 10 | Multi-select: the set of metamorphic clues; the set of rocks that hold water | 005, 006 | hard | 2 |
One exemplar per type, in full
Type 1 (PP-02, EAR4-011, easy, figure pp_look_sheets) — Look at the close-up of a rock's surface. Which family has this look? · sedimentary / metamorphic / igneous · why: Metamorphic rock has grains lined up so it splits into flat sheets. This surface shows thin flat sheets lifting away at the edge. So the family is metamorphic. Blind text (v2, per instance): "a dark purple-gray box of thin flat sheets stacked like pages, the lines between them 7 px apart; at the right edge the top two sheets lift away from the stack, and a pale gap shows under each lifted sheet."
Type 2 (PP-42, EAR4-005, hard — the near miss) — A hard, shiny rock has grains locked together in a jumble, with no layers. Jasper says shiny rocks are metamorphic. Which family is it? · metamorphic / igneous / sedimentary · hard because: hard and shiny (the "often" features) pull toward metamorphic, and the grain clue decides.
Type 3 (PP-31, EAR4-005, medium) — Which of these four rocks is sedimentary? · a rock with wavy bands of dark and light grains / a rock with shell pieces stuck together in flat layers / a rock with grains locked in a jumble / a rock that splits into thin flat sheets.
Type 4 (PP-39, EAR4-012, hard) — Jada finds a white rock whose grains sparkle, with gray wavy stripes. Which rock was it before heat and squeezing changed it? · sandstone / granite / shale / limestone · hard because: two ideas chained — the look names the rock (marble), then the student recalls which rock marble was.
Type 5 (PP-46, EAR4-005, hard) — Granite and gneiss have the same pink, gray and black grains. What tells you that gneiss is metamorphic and granite is igneous? · Gneiss is darker. / Gneiss's grains sit in wavy bands. / Gneiss is heavier. / Gneiss has more black grains.
Type 6 (PP-23, EAR4-012, medium) — Deep underground, a rock becomes a metamorphic rock. What happens to the rock? · It melts, then cools into new rock. / It breaks into pieces that settle. / It dissolves in water, then dries. / It stays solid while its grains change. (v2: the options parallel in length and shape; no claim-maker.)
Type 7 (PP-24, EAR4-012, medium) — A rock deep underground gets so hot that it melts, and later it cools and hardens. Which family is the new rock? · metamorphic / sedimentary / igneous.
Type 8 (PP-52, EAR4-006, hard) — A town drills a well for water into a thick layer of granite, and the well stays dry. What is the reason? · Granite is too hard to drill. / Granite soaked all the water up. / Granite is too heavy. / Granite has no spaces to hold water.
Type 9 (PP-44, EAR4-005, hard, typed) — A rock's grains sit locked together in a jumble, with no layers, and one side of it looks like dark glass. Type the name of its family. · accept: igneous, igneous rock, igneous rocks, an igneous rock, ignious, igneus, ignius, ignous, igneos, ignious rock, igneus rock, ignious rocks, igneus rocks, the igneous family, igneous family. PP-49 (granite) carries wrong_fb for "igneous" / "igneous rock" / "an igneous rock": the family named where the rock's own name was asked.
Type 10 (PP-48, EAR4-006, hard, multi) — Select every rock that can hold water in tiny spaces between its grains. · sandstone / limestone / granite / slate · fb per option.
Draw constraints (⟂: never on one test together) — v2, the blind readers' pairs added
- PP-07 ⟂ PP-21 ⟂ PP-39 (limestone → marble stated or implied in one is another's answer); PP-06 ⟂ PP-39 (marble's look named beside the rock it was); PP-08 ⟂ PP-22 ⟂ PP-40 (shale → slate; PP-08 and PP-22 print PP-40's typed word).
- PP-04 ⟂ PP-45 (the metamorphic looks); PP-14 ⟂ PP-48 (the rocks with tiny spaces); PP-24 ⟂ PP-25 (the two paths).
- PP-23 ⟂ PP-41 (the "stays solid" statement is one's key and the other's option); PP-10 ⟂ PP-26 (deep underground / the rock on top).
- PP-05 ⟂ PP-46 (gneiss's bands stated in one, the deciding feature in the other); PP-19 ⟂ PP-20 (the sheets look as the metamorphic one, both gray rocks); PP-33 ⟂ L03-q9's move (lesson side, no bank constraint).
- PP-35 ⟂ PP-49 ⟂ PP-51 ⟂ PP-52 (PP-35's distractor "a rock with no spaces, like granite" hands the granite items their class).
Design-move inventory (one line per item; move · scene kind · nearest earlier item)
Moves by type (see the table): T1 read a drawn look · T2 sort a described rock · T3 pick the one of four · T4 map a named rock / before-after · T5 pick the sorting clue · T6 state the mechanism · T7 sort a hot rock's path · T8 read tiny spaces · T9 type the name · T10 select the set. Lesson-side instances the bank was read against: L01 quiz (four drawn look boxes y/n; two LOOK3 items; Rock J / Rock K; Jasper's claim; two term MCQs); L02 quiz (lava recall; limestone → ?; shale → ?; quartzite FRQ; three claims; where; transfer; which two things); L03 quiz (four clue cards J K L M; four described rocks; the sorting question; Jasper's claim); L04 quiz (natural-resource recall; drop cards J K; limestone drop; which holds water; roof tile; where oil sits; two claims; bead → no oil); practice PR-1…PR-12; attached and summary items.
| Item | Atom | Tier | Type | Key | Scene kind | Nearest earlier item, and why this is fresh |
|---|---|---|---|---|---|---|
| PP-01 | 011 | easy | 1 | A | drawn bands box → name the LOOK (four looks) | L01-q2 asked y/n on a three-ribbon instance (seed 11); here a two-ribbon instance (seed 19), the blind text per instance, and the look named from four |
| PP-02 | 011 | easy | 1 | B | drawn sheets box → family (3 options) | L01-q3 asked y/n on a green-gray, left-split instance; here a purple-gray, right-split instance and the family from three |
| PP-03 | 011 | easy | 4 | B | grains lined up → what it lets the rock do (four events) | new move: the feature's consequence, not the family |
| PP-04 | 011 | easy | 1 | D | which of four looks is metamorphic | L01-q6/q7 named a look from a description; here the looks are the options |
| PP-05 | 011 | easy | 4 | A | gneiss → family (3 options) | L01's v2 name-recognition items (q10–q12) coin the name as an item first; here the family |
| PP-06 | 011 | easy | 4 | C | marble (hard, sparkles, wavy stripes) → family (3 options) | PR-4 sorts "a white rock" by its look; here the rock is named and all three features given |
| PP-07 | 012 | easy | 4 | C | Georgia limestone → which rock | PR-7 / L02-q2 (a layer of limestone, no place); re-scened to Georgia's mountains |
| PP-08 | 012 | easy | 4 | A | shale → which rock | L02-q3 (shale "made of mud in flat layers"); here no description, the name alone |
| PP-09 | 012 | easy | 6 | C | Jana's mountain rock: which two things changed it | L02-q10 asked bare; here on a named rock |
| PP-10 | 012 | easy | 6 | B | where the change happens (four places) | L02-q8 (three places); fresh distractors (beach, mountain top, river) |
| PP-11 | 005 | easy | 2 | C | a black rock picked up on a hike: glassy, sharp edges, no grains (sentence, 3 options) | v2 re-scene (v1 was L03-q4's card renamed): a found rock on a hike, the sharp edges a new datum |
| PP-12 | 005 | easy | 2 | A | a river cliff's brown rock: sand and pebbles in flat layers (sentence, 3 options) | v2 re-scene (v1 was L03-q6 as a card): a landform, mixed pieces |
| PP-13 | 005 | easy | 2 | A | jumble, no layers (sentence, 3 options) | L03-q1 card J; here pink and gray named, plain sentence |
| PP-14 | 006 | easy | 8 | D | which of four rocks has tiny spaces | L04-q5 (three rocks, "hold water"); here four rocks and the property itself |
| PP-15 | 006 | easy | 8 | B | water on a slate block and a sandstone block → which soaks it in | new move: two blocks predicted together (SUMMARY-3 was one rock, what happens) |
| PP-16 | 006 | easy | 8 | A | table T/V → which can hold | new (a table read one step beyond the cell) |
| PP-17 | 011 | medium | 3 | C | four descriptions → the metamorphic one | new form in the topic |
| PP-18 | 011 | medium | 1 | D | drawn swirls box → which rock | new (marble's look drawn; four rock names) |
| PP-19 | 011 | medium | 5 | B | two gray rocks that both come apart flat: which look shows one is metamorphic | v2 re-scene (v1 was L03-q9's striped rock with the look asked): the SHEETS side of the near miss, the look asked from four |
| PP-20 | 011 | medium | 3 | B | jumble vs sheets, both gray → which is metamorphic | L01-q8 (J bands vs K layers); here the other metamorphic look against igneous |
| PP-21 | 012 | medium | 4 | C | marble ← which rock | new direction (after → before) |
| PP-22 | 012 | medium | 4 | A | slate ← which rock | new direction |
| PP-23 | 012 | medium | 6 | D | a rock becomes metamorphic deep underground → what happens to it (four events, parallel) | v2 re-scene (v1 was L02-q6's claim with gneiss): no claim-maker, the event picked |
| PP-24 | 012 | medium | 7 | C | melts, cools → family (3 options) | L02-q9 was the stays-solid case; this is its boundary twin |
| PP-25 | 012 | medium | 7 | B | hot, squeezed, stays solid → family (3 options) | L02-q9 (three options, "a metamorphic rock"); here the bare family set |
| PP-26 | 012 | medium | 6 | A | the rock on top → what it does | new (the squeezing's cause asked directly) |
| PP-27 | 005 | medium | 2 | B | card N: gray and hard; thin, SMOOTH sheets; grains too small to see, all lined up the same way (3 options) | L03-q5 (sentence); here a card with the "too small to see" competitor — v2: "hard", "smooth" and "lined up" tell it from shale (Topic 18 keyed a "gray, splits into sheets" card sedimentary) |
| PP-28 | 005 | medium | 2 | C | card R: sparkling white, gray wavy stripes (3 options) | PR-4 (sentence); here a card |
| PP-29 | 005 | medium | 1 | A | drawn shells box → family (3 options) | new drawing (shells; v2 seed 17 — three layers, shells scattered, never the teaching box) |
| PP-30 | 005 | medium | 1 | C | drawn glassy box → family (3 options) | new drawing (glassy) |
| PP-31 | 005 | medium | 3 | B | four descriptions → the sedimentary one | new form |
| PP-32 | 005 | medium | 3 | D | four descriptions → the igneous one | new form |
| PP-33 | 005 | medium | 5 | C | a town hall's striped front step: which CLUE proves metamorphic | v2 re-scene (v1 was Jana's rock, L03-q9's scene): a building stone; "flat and straight" the trap |
| PP-34 | 006 | medium | 8 | C | an Ohio farm's well in sandstone → where the water sits | v2 re-scene (v1 was L04-q7 with gas and Ohio): water drawn by a well |
| PP-35 | 006 | medium | 8 | A | Jada's picture of oil flowing in rivers through a cave → what really holds oil (four holders, same shape) | L04-q8 (Jana's lake, bare y/n); here rivers, and the holder picked — v2 Jada, so Jasper is not wrong in every claim |
| PP-36 | 006 | medium | 8 | D | drop card S, a riverbank stone (soaked) → which rock could it be | v2: a seeded card in the neutral rock colour (patch in the middle; L04-q2's J has it right of the middle) and a scene |
| PP-37 | 006 | medium | 8 | A | drop card R, a hillside stone (bead) → what it tells you | v2: a seeded card (drop right of the middle; L04-q4's K has it in the middle); the fourth option "tiny spaces already full of water" replaced by "tiny spaces between its grains" |
| PP-38 | 006 | medium | 8 | B | slate porch floor, drops bead → reason | L04-q6 (roof tile, which rock); here the reason on a floor |
| PP-39 | 012 | hard | 4 | D | white sparkling striped rock → which rock it WAS | chains PP-18's look to PP-21's before rock |
| PP-40 | 012 | hard | 9 | typed | shale → type the new rock | PP-08's move produced, not picked |
| PP-41 | 012 | hard | 6 | A | wavy-banded hillside rock → true statement about its past | PR-10 (yes/no "was once a different rock"); here four pasts |
| PP-42 | 005 | hard | 2 | B | hard, shiny, grains in a jumble; Jasper says shiny means metamorphic → family (3 options) | new near miss on the "often" features (no earlier item uses hard / shiny as the trap) |
| PP-43 | 005 | hard | 5 | B | the rock is sedimentary → which look must it have (four looks) | new direction: family → look (every earlier sort item runs look → family) |
| PP-44 | 005 | hard | 9 | typed | jumble + glassy side → type the family | PP-13's move produced |
| PP-45 | 005 | hard | 10 | multi | select the metamorphic clues | new (set answer) |
| PP-46 | 005 | hard | 5 | B | granite vs gneiss, same grains → what tells them apart | L01 article's pair figure; never asked as an item before |
| PP-47 | 005 | hard | 2 | B | pale, grains too small, flat layers, shell pieces → family (3 options) | L03-q3 card K (shells only); here the competing "too small to see" clue |
| PP-48 | 006 | hard | 10 | multi | select the rocks that hold water | new (set answer) |
| PP-49 | 006 | hard | 9 | typed | speckled, grains in a jumble, no spaces, drop beads → type the rock (granite) | new typed key; two properties, one rock |
| PP-50 | 006 | hard | 8 | C | Rock W soaked → what it could hold deep underground | L04-video (y/n tiny spaces); here the chain to the three resources |
| PP-51 | 006 | hard | 8 | B | water flows past granite and sandstone → which holds it | new (both classes in one scene) |
| PP-52 | 006 | hard | 8 | D | dry well in granite → reason | new (a real outcome's reason) |