Skill: course-build → atomise (architecture re-check, steps 6b/6c) → write-like-james @ df153ae

Grade 4 Science — course architecture v2 (re-checked 2 October 2026 against every ruling since 28 September)

Status: PROVISIONAL — in force from 2 October 2026 under James's ruling "build straight away"; any line he objects to is changed, nothing waits for a click.

Read this in five minutes. Grade 4 Science is ONE course with a fixed order, built the same way as Grade 3. It arranges the 158 Grade 4 atoms into five strands and thirty-eight small topics, each with its own summary video, mixed practice and PP100. Nothing below writes a lesson sentence. The atoms stay where they are: the Science Knowledge Graph's 3-5 registers. Every atom is placed exactly once; no atom's prerequisite comes after it (checked again on 2 October, see "Checks run").

Decisions I need from you

The first two changed since the 28 September plan. The other four are the 28 September questions, still open, with the same recommendations. I am building on every recommendation below; say so if you want any of them the other way.

1. Is engineering design its own strand in Grade 4, two topics long, placed after Physics?

Context: you said on 1 October "in Grade 4 we may want to consider it as a separate strand". The Grade 4 design atoms are four: what a design must do, what it must stay inside, design a solution, test the design against the rule.

Context: the three-lesson demo you reviewed on 2 October (the bird feeders) already teaches the first three, in the course schema, videos rendered. The fourth needs the fair test (Topic 2) and a real build to test, and the energy-changer build (NGSS 4-PS3-4, "design, test and refine a device that converts energy") is that build.

Recommendation: a fifth strand, "Design and build", of two topics after Physics: Topic 11 is the demo as built (3 lessons); Topic 12 "How to build and test an energy changer" (4 lessons: moving air and water turn things, spot the energy change, build the changer, test it against the rule). The 28 September plan's seven-lesson Topic 11 goes away. The strand gets its own short intro video and NO end-of-strand test (two PP100s certify seven atoms).

Choices: fifth strand as recommended / weave the four atoms into Physics as one seven-lesson topic (the 28 September plan) / fifth strand but with a strand test too.

2. Does the summary video come before the mixed practice in Grade 4?

Context: for the demo on 2 October you ruled "the summary comes BEFORE the mixed practice". Grade 3 runs practice → summary → PP100 (the 25 September ruling for grades 3-8).

Context: with the summary first, the child hears every rule once, then practises, then sits the PP100 with the practice fresh. The page order is a one-line flag per topic; Grade 3 is untouched until you say.

Recommendation: yes, summary → practice → PP100 for Grade 4.

Choices: yes / keep Grade 3's order (practice → summary → PP100) / change Grade 3 too.

3. Does Grade 4 physics open straight on friction, with retrieval items from Grade 3 instead of a re-teach?

Context: Grade 4 has no motion atoms and nothing re-teaches balanced and unbalanced forces; friction's only prerequisite is Grade 3's "a push or pull can slow or stop things".

Context: Olivia asked for cross-grade retrieval; two or three Grade 3 items in Topic 1's practice set give it without a re-teach lesson.

Recommendation: friction first; retrieval items only.

Choices: as recommended / a re-teach topic with new atoms.

4. Is the fair test taught on the friction investigation (Topic 2)?

Context: "test friction on different surfaces" needs "keep everything else the same", so the five fair-test lessons come just before it, in one six-lesson topic that is one investigation from question to result.

Recommendation: yes, Topic 2 as drawn.

Choices: yes / move the fair test to the energy-changer build.

5. Does "water's states at work" stay in Matter, next to "same material or new material"?

Context: Matter uses water freezing, melting and evaporating as its reference case for "same material, changed". The water cycle (Topic 23) uses the same idea seven topics later and retrieves it in one line.

Recommendation: keep it in Matter.

Choices: keep / move to open the water cycle.

6. Do the three energy-resource topics sit in Earth & Space, after the water cycle and climate?

Context: wind, moving water, sunlight, plants and the three fuels are Earth's resources (TEKS 4.11, Florida 4.E.6.3); the one Physics atom among them (moving air and water can turn things) is taught in Topic 12.

Recommendation: Earth & Space, as drawn.

Choices: Earth & Space / end of Physics.

Applied without asking (your rulings already given): the strand order Physics → Matter → Earth & Space → Life, with Design and build slotted after Physics (decision 1); Scientific Reasoning taught inside the topics that use it, no SR strand test; topics of three to six atoms, none over six; the water cycle taught once, here, with the ocean; the Moon "why" atom in, seasons patterns-only; one atom one lesson, video or article; an intro per strand and per topic that teaches nothing; "criterion" and "constraint" ARE coined in Grade 4 and used from then on (your demo notes of 2 October: "we already have introduced criterion and constraint so that's what we should be using now"), so the register's SR4-021 note "everyday wording only" is proposed for retirement in the knowledge-graph repo; the pattern-and-predict practice sits where the pattern is the science (the Sun's path, the seasons, the Moon's shapes, which are already atoms there), with "a pattern is something that happens again and again in the same way"; predator and prey are Grade 5 words, Grade 4 says "the fox eats the rabbit"; every topic title fits the frame "Here's everything we found out about ___"; the language rules (Earth's pull, carriers not forms, no "leak" or "lift", "stuff" beside "matter", "density" named); grade-4 codes that restate grade-3 content are cited on the grade-3 atoms, no clones; the strand tests are placeholders until Becky's format gate is passed (Grade 3's proposal of 30 September applies as written); names a child can spell, one topic each, US animals, US spelling; "strand" never said to a student.

Card 1 — The strands and their order

The call: Physics → Design and build → Matter → Earth & Space → Life, each with its own intro video; a strand test after Physics, Matter, Earth & Space and Life (placeholders under Becky's validation), none after Design and build.

Scientific Reasoning's 12 atoms are spread through Topics 2, 11, 12 and 25 (Card 3). Total 158 lessons.

Card 2 — The topics

The call: thirty-eight topics of three to six lessons; a summary video, a mixed mastery practice set and a PP100 at the end of every one. Every topic is one PP100 cluster, closed by the capstone atom named in the last column.

Totals: 158 lessons, 38 practice sets, 38 PP100s (banks of at least 50 items each, at least 5 per atom), 4 strand-test placeholders (after Topics 10, 16, 32, 38), 1 end-of-grade test.

Why this grouping

• Every prerequisite edge points backwards in this order or into Grade 3. Checked atom by atom in the assembled files on 2 October (see "Checks run"); zero forward references.
• Topic 2 puts the fair test right where it is first needed (FOR4-004 requires SR4-003), so every later investigation in the year can call on it, including Topic 12's test of the design.
• Topic 12 needs Topic 4 (energy from giver to receiver, the carriers) for "spot the energy change", Topic 2 for the fair test, and Topic 11 for the criterion and constraint the build is tested against. After Physics is the earliest place all three hold.
• Topic 8 (waves) sits before Topic 22 (seismic waves need ENE4-040); Topic 21 (rock layers) sits before Topic 38 (reading past environments needs EAR4-036).
• The rock families are taught one family at a time, what it looks like then how it forms, and only then the sort (the 25 September ruling on the six per-family atoms). Topics 18 and 19 split them so no topic reaches seven.
• Energy resources follow Olivia's rule of surprising members first: wind, water, sunlight and plants (Topic 27) before the fuels everyone already calls "energy" (Topic 28), then the renewable-or-not sort on all seven (Topic 29).
• Topic 7 pairs sound and sight because both answer one question, "what has to reach you for you to hear or see?"; the two seeing atoms are too few for a topic of their own.
• No topic reaches seven lessons; none has fewer than three.

What changes: the folder gets grade4/topicNN_build/ per topic as each is built; Topic 11 is grade4/demo_criteria_constraints/ re-pointed as a topic folder (its code G4DEMO stays on the five live videos).

Card 3 — Scientific Reasoning is taught where it is used

The call: each of the 12 Scientific Reasoning atoms is a lesson inside the topic that first needs it, with its check there; no separate strand, no separate test.

Card 4 — Tests and benchmarks

The call: a PP100 per topic; a static end-of-strand test per strand except Design and build (placeholders until Becky's format gate is passed); one static end-of-grade test; all Grade 4 tests are our own banks, seeded from released grade-5 items filtered to Grade 4 atoms.

• No state tests science at grade 4 (D1 ruling). The released STAAR, Florida SSA and AZSCI grade-5 forms are cumulative over grades 3-5, so their items tagged to Grade 4 atoms seed the banks and set the style.
• Grade 4 content the grade-5 tests lean on hardest: the water cycle and the ocean (Topics 23-24, STAAR 5.10A builds on them), weathering-erosion-deposition (Topic 20, feeds STAAR 5.10C landforms), circuits (Topics 9-10, feeds 5.8B), mixtures and "the mass holds" (Topics 14-15, feed 5.6B and 5.6C), food webs and producers-consumers-decomposers (Topic 35, feeds 5.12B), the Moon's shapes and Earth's spin (Topics 31-32, feed 5.9A).
• The strand-test placeholders fall after Topics 10, 16, 32 and 38; the format is the Grade 3 proposal of 30 September (30 items, 27 to pass, three protected forms), unchanged until Becky rules.
• The end-of-grade test samples all four science strands plus Design and build, with free-response items.

Checks run (2 October 2026, re-run on the assembled files)

• Atoms placed: 158 = atoms in the Grade 4 registers (FOR4 10, ENE4 31, MAT4 13, EAR4 52, SPA4 14, LIF4 26, SR4 12). Every atom appears in exactly one topic; none is left over; none is doubled.
• Prerequisites: every prerequisite of every Grade 4 atom sits in an earlier topic of this plan, earlier in the same topic, or in Grade 3. Zero violations (script output in grade4/records/ARCHITECTURE_CHECK_2026-10-02.txt).
• Titles: every topic title fits "Here's everything we found out about ___".
• Topics of 7+: none. Topics of 2 or fewer: none.

What happens next

Topic 1 ("Why sliding things stop") gets its blueprint in the Grade 3 shape, then its lessons, quizzes, summary, practice, PP100 bank and scripts, straight through; the Grade 3 Forces golden pack is checked for reuse (FOR3-003's "a push or pull can slow or stop things" is friction's doorway). Topics follow in order. A lesson whose best teaching is genuinely uncertain comes to James as one question on the topic's decisions page; nothing else waits.