Skill: course-build → write-mcqs → write-explanation, design-check-sequence @ a5ff054 · revised after the non-author review (28 Sep 2026, night)
Topic 13 — Light: sources, straight lines, shadows — the PP100's seven question types, with their exemplars
What this page is. James approves a bank's question TYPES before the bank is generated (vault: A bank is reviewed as its question types first, one exemplar each, 28 Sep 2026). This sheet writes the exemplars in full, exactly as they sit in content/G3T13.py (PP100, flagged TYPE_SHEET_ONLY). Seven types, seven exemplars (type 1 carries a second case, the Moon; type 3 is folded into type 6, below), at most two types per atom. No other bank item exists yet. Once the types stand, about fifty items are generated from them, varying scene and nouns, easy-heavy.
Revised 28 Sep (night) after the non-author review (REVIEW_G3T13_2026-09-28.md): every exemplar is now a fresh instance with a figure that matches its stem; no stem prints its answer or names the source as the grammatical subject; the two typed items are two-step (a moved lamp; a chain of two atoms) so they are genuinely harder than the quiz; the sort sentence is "a light source makes light" throughout. James's standing reminder: the two typed hard items were re-authored tonight and need his re-review.
James's ruling of 28 Sep (night), applied here: the hard types are TYPED items, not MCQs. Types 6 and 7 are text items with an accept list in the lesson's words (the grader ignores case, articles and a final period); the easy and medium types are four-option MCQs and the bulk of the bank.
How to read a type line. Each says what the stem asks, what the options (or the typed answer) are, and gives its exemplar scene. Every MCQ has four options and a why (no per-option feedback in the bank). Tags follow depth of reasoning: easy = one-step sort or the fact; medium = a fresh case that needs a reason or the fact applied against a trap; hard = two steps of the skill, typed. No option bundles a verdict with a reason; every stem is a positive question; no item figure draws the shadow or a light line except the path item, where the paths are the thing judged; no bank item shows a reference card.
The seven types
| Type | Items | Atom | Tag | The stem asks… | The options / the typed answer are… | Exemplar scene |
|---|---|---|---|---|---|---|
| 1 | PP-1, PP-2 | ENE3-010 | easy | a night scene is described (what is on, what is bright); which thing is the light source | four things from the scene; exactly one makes light. The second case puts the Moon among them (the register's LGT-06 trap; James may strike it) | a streetlight, a parked car, a mailbox, a tree · the Moon, a streetlight, a parked car, a mailbox |
| 2 | PP-3 | ENE3-011 | easy | which of four drawings shows how light travels from a flashlight to a wall | drawing J / K / L / M (straight, zigzag, looping, curved — a different order and a different source from the lesson quiz's three-panel item); the letters lie outside A–D | a flashlight and a wall (figure pp_paths_four) |
| 3 | — | ENE3-012 | — | (folded into type 6: the shadow's side is asked as a typed item, so the atom keeps two types and no easy MCQ of its own; the lesson quiz carries the MCQ form) | — | — |
| 4 | PP-4 | ENE3-011 + ENE3-012 (pair) | medium | a shadow's place is described; why is the shadow there | four single-statement reasons; the key is that the object blocks the light from reaching the surface behind it; the distractors are the catalogue's LGT-05 beliefs — the light pushes the shadow out, the shadow comes out of the object, the object's dark side shows | a flashlight, a toy car on the floor, its shadow to the left |
| 5 | PP-5 | ENE3-017 | medium | a child in a place with no light at all, for a stated time: what does she see | four things seen (faintly / nothing / clearly / only one thing); the key is nothing; the LGT-02 trap ("eyes adjust") sits in the first option | Nadira in a cellar for ten minutes |
| 6 | PP-6 | ENE3-012 | hard · TEXT | a lamp is to one side of an object; then the lamp is moved to the other side; on which side is the shadow now | typed: right / the right / the right side / on the right / to the right of the bottle / right-hand side …; the stem never prints the answer | a lamp moved from the right of a bottle to its left |
| 7 | PP-7 | ENE3-010 + ENE3-017 (pair) | hard · TEXT | in a shed with no light, a flashlight is pointed at a shelf and he sees it: just before the light reaches his eyes, which thing does it come from | typed: the shelf / shelf / from the shelf / off the shelf …; most students will type "the flashlight" | Soren, a shed, a flashlight, a shelf |
Coverage (every atom alone, and the pairs)
| Atom | Types testing it alone | Pair types |
|---|---|---|
| ENE3-010 light comes from a source | 1 | 7 (with 017) |
| ENE3-011 light travels in straight lines | 2 | 4 (with 012) |
| ENE3-012 predict the shadow | 6 (typed) | 4 (with 011) |
| ENE3-017 seeing needs light reaching the eye | 5 | 7 (with 010) |
Two types per atom, no more. Order in the file: easy → medium → hard (PP-1 … PP-7). MCQ keys: C D A D B (five MCQs over four letters, so one letter repeats once; it clears as the bank grows). Typed items carry no key letter. Draw-one-per-test pairs for the generation step: PP-1 with L01-q1 (a streetlight, different move); PP-3 with L02-q4 (four drawn paths vs three, different source); PP-5 with L04-q3 (a cellar, different move).
The exemplars, in full
Type 1 — PP-1 · ENE3-010 · easy
Stem: At night, a streetlight is on, and under it a parked car, a mailbox and a tree are all bright. Which thing is the light source?
- a) the parked car
- b) the mailbox
- c) the streetlight ← key
- d) the tree
Why: The streetlight makes light. / The light lands on the car, the mailbox and the tree, and they are lit up. / A light source makes light, so the streetlight is the light source.
(The scene is described — what is on, what is bright — so the student infers the source; the stem no longer says the streetlight "lights up" the others.)
Type 1, second case — PP-2 · ENE3-010 · easy (the Moon; James's call)
Stem: At night, the Moon is bright in the sky, and a streetlight is on above a parked car and a mailbox. Which thing is the light source?
- a) the Moon
- b) the parked car
- c) the mailbox
- d) the streetlight ← key
Why: The streetlight makes light. / Sunlight lands on the Moon, and the Moon is lit up; the Moon does not make light. / The car and the mailbox are lit up too, so the streetlight is the light source.
Type 2 — PP-3 · ENE3-011 · easy · figure pp_paths_four
Stem: Four drawings show light leaving a flashlight and reaching a wall. Which drawing shows how the light travels?
- a) drawing J ← key
- b) drawing K
- c) drawing L
- d) drawing M
Why: Light travels in straight lines. / Drawing J shows straight lines from the flashlight to the wall. / Drawings K, L and M show zigzag, looping and curved paths, and light does not travel like that.
Type 4 — PP-4 · ENE3-011 + ENE3-012 · medium
Stem: A flashlight is to the right of a toy car on the floor, and the car's shadow is on the floor to its left. Why is the shadow there?
- a) The flashlight pushes the car's shadow out behind it.
- b) The shadow comes out of the car and lands on the floor.
- c) The car's dark side shows on the floor behind it.
- d) The car blocks the light from reaching the floor behind it. ← key
Why: Light travels in straight lines from the flashlight. / The car blocks some of the light, and light cannot bend around it. / No light reaches the floor behind the car, so that dark place is the shadow.
Medium because: the reason rests on two ideas (straight lines; blocking) applied to a fresh scene, against three catalogued beliefs about shadows. Every option is one statement of the same shape.
Type 5 — PP-5 · ENE3-017 · medium
Stem: Nadira sits in a cellar with the door shut and no light at all for ten minutes. What does she see?
- a) the walls, faintly
- b) nothing ← key
- c) the walls, clearly
- d) only the door
Why: The cellar has no light at all. / No light comes from the walls or the door to Nadira's eyes. / You see something only when light from it reaches your eye, so she sees nothing, however long she waits.
Medium because: the register's trap ("eyes adjust") sits in option a, and the stated ten minutes invites it; the student applies the rule against the pull of the trap.
Type 6 — PP-6 · ENE3-012 · hard · TEXT
Stem: A lamp is to the right of a bottle on a table. Then the lamp is moved to the other side of the bottle. On which side of the bottle is the shadow now?
Accept: right · the right · right side · the right side · on the right · to the right · on the right side · the right side of the bottle · to the right of the bottle · right of the bottle · on the right of the bottle · right-hand side · the right-hand side
Why: The lamp was to the right of the bottle, so the shadow was on the left. / Now the lamp is to the left of the bottle. / The bottle blocks some of the light, and the shadow is on the side away from the lamp: the right side.
Hard because: two steps of the skill — place the lamp after the move, then place the shadow away from it — and the answer is typed, with nothing in the stem to recognise (the stem prints neither side).
Type 7 — PP-7 · ENE3-010 + ENE3-017 · hard · TEXT
Stem: Soren is in a shed with no light at all. He turns on a flashlight, points it at a shelf, and now he sees the shelf. Just before the light reaches his eyes, which thing does it come from? Type the name of the thing.
Accept: the shelf · shelf · from the shelf · off the shelf · the shelf's light · light from the shelf · a shelf
Why: The flashlight is the light source, so it makes light. / The light lands on the shelf. / Then light comes from the shelf to Soren's eyes, and you see something only when light from it reaches your eye.
Hard because: two atoms chained — the flashlight makes the light and it lands on the shelf (010); seeing the shelf needs light FROM THE SHELF reaching the eye (017). Most students answer "the flashlight"; the key needs the second step. "Shelf" is scene data, not the key's word. The stem's four sentences are within the hard tag (sweep S23).
Reading notes for the review
- The verdict-and-reason option form is not used anywhere. Claims in the topic are bare yes / no in the lesson quizzes and practice (Teodora no · Odette yes · Bruno yes · Odette no · Lukas yes · Yusra no · Petra yes · Halima yes), never in the bank.
- Typed accept lists hold the lesson's words and their natural typed forms (articles, "side", "of the bottle", "-hand side"); no synonym the lesson did not teach.
- Scenes here are fresh against the lessons (lamp and book; flashlight and wall; the Sun and a slide; a candle; the page; the Moon; the attic beam; curtains; the tube; the hand; the ball; the box and dinosaur; the cave; the lamp itself), against the lesson quizzes and against the practice set; the three draw-one-per-test pairs above share a scene kind with a quiz item on a different move.
- Not planned: any multi-select; none of these answers is a set. No numeric item: nothing in the topic is a number.
- Names used in this topic: Teodora, Odette, Greta, Petra, Yusra, Bruno, Amaru, Marisol, Adaeze, Lukas, Tavi, Joss (quizzes); Hollis, Halima (practice); Wilbur (summary); Nadira, Soren (bank). Checked by grep against every other topic's content files: none collides.