Skill: course-build → write-mcqs → write-explanation, design-check-sequence @ efd8fba
Topic 31 — The turning Earth and the stars — the PP100's question types, with their exemplars (v1, 2 October 2026)
In one line: 52 items, 47 four-option MCQs and 5 typed (24, 365, orbit, year, Earth); eighteen types, because the five atoms each need a fact form, an apply form and a claim form, and the capstone needs the "what is really moving" form and the rule run backwards. MCQ keys A 11 · B 12 · C 13 · D 11. Difficulty rises with the atom's order: SPA4-007 (the spin) seven easy, three medium, one hard typed number; SPA4-008 (the trip) four easy, four medium, four hard (one chained, three typed); SPA4-005 (patterns keep shape) three easy, five medium, two hard; SPA4-006 (seasons) six medium, two hard; SPA4-009 (the capstone) six medium, five hard.
What this page is. James reads a bank as its question TYPES first (vault: A bank is reviewed as its question types first, one exemplar each). Under the Grade 4 standing brief the bank is built straight away (content/G4T31_pp100_bank.py); this sheet is the way in. Each type line says what the stem asks, what the four options (or the accept list) are, and prints one exemplar in full with its nearest lesson-side instance, so freshness can be checked in one look.
Rulings already applied. Four options on every MCQ (three fixed sets: HOW LONG "about 1 hour / about 24 hours / about 7 days / about 365 days", used for the spin AND the trip so the key tells them apart; WHAT WE CALL "an hour / a day / a week / a year"; WHAT IS REALLY MOVING, every option a short full sentence — the Sun stem "Earth is spinning around. / The Sun is traveling around Earth. / The whole sky is turning around Earth. / The clouds are pushing the Sun along."; the stars stem swaps in "The stars are flying across space." and "The wind is blowing the stars along."; the Moon stem "The Moon is sliding across the sky on its own." and "The wind is blowing the Moon along." — never "the Moon is traveling around Earth", which Topic 32 teaches as true; rotated per item); no option bundles a verdict with its reason (every claim is "X is wrong … What is the correct reason?" with four single-statement reasons; the one TRUE claim is "Paul is right that … What is the correct reason?"); every stem is a positive question of at most two sentences unless tagged hard (S23 clean); the lettered items read their letters from figures.LETTERS (one list for stem and drawing) and their blind text is data (which letter the dot or Earth sits at; the stars' positions as numbers), never the answer; the key is never the longest option by the key-tell checker's margins (check_key_tells.py: 0 of 107 flagged, v2); "star pattern" and "constellation" are recalled by MCQ (RECALL_BY_MCQ, eleven and thirteen letters); the typed keys are the numbers 24 and 365, and the words orbit (Grade 3's term), year and Earth (a name), with child spellings in the accept lists; no multi-select; every item names ONE atom; US spelling; units as words in prose, numerals on drawings.
The bar list (real things a generated item must never use): "axis", "rotate", "revolve", "hemisphere", "equator", "tilt", "leap year" (not taught); any cause of the seasons or of day and night (grade 5 / grade 6-8); the Sun or the stars "moving" (they "seem to move"); the Moon's monthly changes (Topic 32's); any lesson scene (the classroom globe and its sticker, Andre's birthday cake, Phoebe's grandmother's farm porch and barn in Kansas, Paul's Dallas backyard with his dad and the fence, Andre's car on the highway to San Antonio, the intro's bedroom window); any quiz, attached or practice scene (the spelling test, Andre's uncle, Phoebe's cousin, the fair ride, the anchored boat, the lighthouse, the tree ring, the school clock, the crown and fish patterns, letters J K L M); a claim-maker from another topic's row (only Paul, Andre and Phoebe); "biggest / smallest" for a time or a count (longest, most); a non-US sky name (the Plough).
The eighteen types
| Type | Items | Atom | Tags | Form | The stem asks… | The options / the accept | Exemplar scene |
|---|---|---|---|---|---|---|---|
| 1 | 2 | 007 | easy | MCQ, HOW LONG set / an hours set | how long one spin takes | about 1 hour / 24 hours / 7 days / 365 days | a scientist in Alaska timing one spin; Phoebe counting the hours |
| 2 | 3 | 007, 008 | easy | MCQ, WHAT WE CALL set | what we call the time of one spin / one trip | an hour / a day / a week / a year | sunrise to sunrise in Oregon; Tuesday 7 AM to Wednesday 7 AM; one trip back to the start |
| 3 | 2 | 008 | easy | MCQ, HOW LONG set / an age set | how long one trip takes; how old after one trip | the set; one day / week / month / year old | a scientist in Hawaii; Phoebe's baby brother |
| 4 | 3 | 007, 008 | easy | MCQ, counts | how many spins in 3 days / one week; how many trips in 3 years | once / 3 / 7 / 24 / 30 / 365 times | a Michigan lake stay; a Colorado camp; Andre's dog |
| 5 | 2 | 007 | easy, medium | MCQ, drawn disc | where the town dot is after 24 hours (back) / after 12 hours (opposite) | the four letters | letters N P Q R; S T V W |
| 6 | 2 | 008 | medium | MCQ, drawn orbit | where Earth is one year on (back) / 6 months on (opposite) | the four letters | letters N P Q R; S T V W |
| 7 | 2 | 007, 008 | medium | MCQ, the correct reason | why nobody can feel the spin (smooth and steady, not slow); why a year is 365 days | four single statements | — |
| 8 | 4 | 009 | medium | MCQ, WHAT IS REALLY MOVING sets | what is really moving when the Sun / stars / Moon seem to; what is really happening as the Sun comes up and goes down | the Sun set; the stars set; the Moon set (full sentences) | a Florida beach; a Nevada desert; the Moon; east to west |
| 9 | 6 | 007, 008, 005, 006, 009 | medium, hard | MCQ, claim | X is wrong … the correct reason (spins once an hour; one trip a day; the Dipper's stars move apart; stars only at night; the Sun travels around Earth; two movers for Moon and stars) | four single-statement reasons, three half-accepting the belief | — |
| 10 | 3 | 005 | easy | MCQ, the term | what a group of stars in a shape is called; the other word people who study the stars use; which of four things is a star pattern | a star pattern / a group of planets / a telescope / a cloud; a constellation among sisters; four things | Montana's cross; the stars' other word; a kite |
| 11 | 3 | 005 | medium | MCQ, drawn sky pair (the bank's own patterns: an M, an arrow, a cross) | how many stars moved on their own; what the group did between the times; which is true at the later time | none / one / two / all five; four happenings; the 2 × 2 place-shape form | an M at 7 and 10 PM; an arrow at 10 PM and 1 AM; a cross at 9 PM and midnight |
| 12 | 2 | 005 | medium | MCQ, no drawing | what differs between two photos of a pattern three hours apart; which is true at midnight | four statements; the 2 × 2 form | Phoebe's aunt's photos of an arrow in Vermont; a pattern above a Colorado mountain |
| 13 | 5 | 006 | medium | MCQ, seasons | will a winter pattern be up in summer; when it comes back; what a year's watching shows; TRUE claim's reason; January to July | four statements | a boat pattern; the big triangle; Andre's year of watching |
| 14 | 2 | 006, 009 | medium | MCQ, the correct reason | why the big triangle is gone in January; why every pattern moves together | four single statements | the big triangle; Maine's sky |
| 15 | 1 | 009 | medium | MCQ, transfer | what is really moving on a slowly turning floor | the person / the walls / the ground / the air | an Ohio museum |
| 16 | 5 | 007, 008, 009 | hard | typed | the number of hours in one spin; the days in one trip; the path's name; the time of one trip; the thing really turning | 24 …; 365 …; orbit …; year …; Earth … (child spellings included) | — |
| 17 | 4 | 008, 005, 006, 009 | hard | MCQ, two steps | 365 spins → one trip; what can be copied from an 8 PM drawing (shape, not place); when a winter pattern is next written in a notebook; a pattern higher at midnight means Earth has turned | four statements | Andre's family's move to Austin; Andre's drawing; Andre's notebook; a Utah hill |
| 18 | 1 | 009 | hard | MCQ, the rule run backwards | what the star patterns would seem to do if Earth stopped spinning | stay in one place / still move / move the other way / change shape | — |
Hard because — type 9 (hard items): the belief is held against the rule and every distractor half-accepts it, so the key is not the odd one out. Type 16: the number or word is produced, not picked, from a fresh scene with no clue word in the stem. Type 17: two ideas chained (spins → days → one trip; shape stays and place changes; the season cycle and the year; the observed move and its cause). Type 18: the cause removed, the effect predicted.
One exemplar per type, in full
Type 1 (easy, SPA4-007). A scientist in Alaska times one whole spin of Earth. About how long is it? — about 1 hour / about 24 hours / about 7 days / about 365 days. Why: Earth spins all the way around once in about 24 hours. So one spin takes about 24 hours. (nearest lesson-side instance: L01-q1, the bare question with three options — here a timer and the four-option set)
Type 2 (easy, SPA4-007). From sunrise in Oregon until the next sunrise, Earth spins all the way around once. What do we call that amount of time? — an hour / a day / a week / a year. (nearest: L01-q5, the bare term question — here the scene is a place and a sunrise)
Type 3 (easy, SPA4-008). A scientist in Hawaii times one whole trip of Earth around the Sun. About how long is it? — about 1 hour / about 24 hours / about 7 days / about 365 days. (nearest: L02-q2, three options)
Type 4 (easy, SPA4-007). Andre's cousin spends one week at a camp in Colorado. How many times does Earth spin all the way around in one week? — 7 times / once / 24 times / 30 times. (nearest: L01-q6, the Friday spelling tests)
Type 5 (medium, SPA4-007, drawn). The red dot on this drawing of Earth is a town, at W. Where will the dot be after 12 hours? — S / T / V / W. Figure pp_spin_stvw; blind text: the letters' places and the dot at W. Medium because the half turn must be read as the opposite side. (nearest: L01-q3, the dot at J after 24 hours)
Type 6 (medium, SPA4-008, drawn). Earth is at T on its orbit today. Where will Earth be 6 months from today? — S / T / V / W. Figure pp_orbit_stvw. (nearest: L02-q3, Earth at J after 6 months)
Type 7 (medium, SPA4-007). Nobody on Earth can feel Earth spinning. What is the correct reason? — Earth spins very smoothly and steadily. / Earth is not really spinning. / Only the land spins, and the people stay still. / The air holds everyone still. (nearest: L01-q7, Andre's claim as yes / no)
Type 8 (medium, SPA4-009). From a beach in Florida, the Sun seems to move across the sky from morning to evening. What is really moving? — Earth is spinning around. / The Sun is traveling around Earth. / The whole sky is turning around Earth. / The clouds are pushing the Sun along. (nearest: L05-q2, three options, no place)
Type 9 (hard, SPA4-009). Paul says the Sun travels around Earth once a day, and that is why it seems to cross the sky. Paul is wrong. What is the correct reason? — Earth spins once a day, so the Sun only seems to move. / The Sun travels around Earth once a year, not once a day. / The Sun stays still and the sky turns around Earth. / The Sun crosses the sky because the wind pushes it. Hard because: the catalogued belief (Baxter 1989; Vosniadou and Brewer 1994) is held against the rule, and every distractor half-accepts it. (nearest: L05-q4, the same claim as bare yes / no)
Type 10 (easy, SPA4-005). Five bright stars make the shape of a cross in the night sky over Montana. What is a group of stars like this called? — a group of planets / a star pattern / a telescope / a cloud. (nearest: L03-q5)
Type 11 (medium, SPA4-005, drawn). Here are five stars at 7 PM and at 10 PM. How many of the five stars have moved on their own, away from the others? — none of them / one of them / two of them / all five of them. Figure pp_m_two (an M pattern); blind text: each star's position as numbers in both panels. (nearest: L03-q2, the kite as yes / no — a different move: a count of movers on a different pattern)
Type 12 (medium, SPA4-005). At 9 PM a star pattern is just above a mountain in Colorado. Which is true at midnight? — The pattern is in a new place, in the same shape. / … in the same place, in a new shape. / … in a new place, in a new shape. / … in the same place, in the same shape. (nearest: L03-q9, two options)
Type 13 (medium, SPA4-006). A big triangle of three bright stars is in the evening sky every July. After it goes, when will the triangle next be in the evening sky? — next week / next month / never / next summer. (nearest: L04-q4, three options)
Type 14 (medium, SPA4-006). The big triangle is in the evening sky in July but not in January. What is the correct reason? — In January its stars stop shining. / In January it moves far away from Earth. / In January it is up by day, hidden by sunlight. / In January the clouds hide it from us every night. (nearest: L04-q5, Orion in July — here the summer pattern in winter)
Type 15 (medium, SPA4-009). Paul stands on a slowly turning floor at a museum in Ohio, and the walls of the room seem to go past him. What is really moving? — The walls are moving around him. / The ground under the museum is turning. / Paul is turning with the floor. / The air in the room is moving him. (nearest: L05-q5, Phoebe on a fair ride)
Type 16 (hard, SPA4-009, typed). The Sun, the Moon and the stars all seem to move across the sky. Type the name of the thing that is really turning. — accept: Earth, the Earth, earth, planet Earth, our planet, erth … Hard because: the name is produced, not picked. (nearest: L05-q2, the MCQ form)
Type 17 (hard, SPA4-005). Andre draws a star pattern at 8 PM. At 11 PM he wants to draw it again without looking up. What can he copy from his first drawing? — the shape of the pattern / the place of the pattern in the sky / both the shape and the place / neither the shape nor the place. Hard because: two steps — the shape stays, the place changes, then the right one is chosen. (nearest: L03-q7, what Paul sees over two hours)
Type 18 (hard, SPA4-009). Imagine Earth stopped spinning. What would the star patterns seem to do at night? — still move across the sky / stay in one place in the sky / move across the sky the other way / change their shapes. Hard because: the rule run backwards. (nearest: L05-q9, the Sun version as two options — a different sky, the same move; the quiz item is on the Sun and this one on the stars)
⟂ draw constraints (an item that prints another's answer, or a near-twin pair; the test builder draws one per test)
- PP-1 ⟂ PP-2 (one spin: the HOW LONG set and the hours set). PP-3 ⟂ PP-4 (what we call one spin). PP-8 ⟂ PP-10 (one trip: the set and the age). PP-9 ⟂ PP-43 (what we call one trip, MCQ and typed). PP-42 ⟂ L02's lexicon line in no bank item (orbit is defined only in its own stem).
- PP-17 ⟂ PP-1, PP-2, PP-39 (Andre's hour claim prints "about 24 hours", the answer to the spin items and the typed 24). PP-21 ⟂ PP-8, PP-19, PP-41 (Phoebe's claim prints "about a year"). PP-19 ⟂ PP-41 (the reason prints 365 days).
- PP-22, PP-23, PP-24 (three drawn pairs on one move) — one per test. PP-25 ⟂ PP-26 (the kite watcher and the 2 × 2 form). PP-27 ⟂ PP-32 (a winter pattern in July, two scenes). PP-33, PP-34, PP-35, PP-38 (WHAT IS REALLY MOVING, four scenes) — two per test at most. PP-49 ⟂ PP-36 (both trace the whole sky to one turning thing).
- PP-46 (the notebook) prints "winter … next winter" as its reasoning, the answer to PP-27 and PP-32: never the same test.
- Added in v2 (2 Oct 2026): PP-24 ⟂ PP-26 (the 2 × 2 place-shape form, drawn and undrawn). PP-30 ⟂ PP-32 ⟂ PR-9 (the "up by day, hidden by sunlight" reason, three scenes). PP-42 (typed orbit) ⟂ nothing now: "orbit" is stripped from PP-10 / 18 / 19 and from every option in the bank; L02-q10 stays last in its quiz.
v2 — 2 October 2026 (the fix pass; records/BUILD_RECORD_G4T31.md, v2 section)
Pedro is Andre throughout. Every WHAT IS REALLY MOVING option is a short full sentence, and the stars and Moon stems have their own distractors (the bank's three MOVING* sets). The SPA4-005 block is re-patterned and re-cased (an M, an arrow, a cross; a count of movers; two photos compared; the triangle in January) so no bank drawing or move is L03's with the chips changed. PP-16's key reads "smoothly and steadily". PP-28 / PP-47 key "next summer" / "next winter" against real distractors. Counts unchanged: 52 items, 47 MCQ + 5 typed, keys A 11 · B 12 · C 13 · D 11, tiers 14 / 24 / 14. check_key_tells.py: 0 of 107 flagged.
v3 — 2 October 2026 (the polish after Reader C's full re-read; records/BUILD_RECORD_G4T31.md, v3 section)
Two bank keys matched to their distractors' shape: PP-23 "It has kept its shape as it moved." (type 11; the comma clause is gone) and PP-44 "The stars keep the same shape all night." (type 9; the only "and" is gone). The typed YEAR list no longer accepts "365 days", "12 months" or "twelve months" where the stem asks for the NAME of the time; each gets its own feedback line (YEAR_WRONG), and the quizzes' and practice set's "day" and "year" items do the same for "24 hours". PR-10's watcher is on a boat held still by its anchor (a ship at sea really is moving, so its old distractor was a second true option). No key letter, tag, type or figure changed; check_key_tells.py: 0 of 107 flagged.