RS4K Book 2 — Astronomy (Ch 18-21): K-2 atoms-first chapters. Foundation 100%, Gap 0.0%, Map Error 0.0%, Practices 92.9%, no FSEs. Telescopes, orbits, habitable zone, exoplanets all framed at appropriate scale. Greenhouse effect named as causal CO2 mechanism. Recommended Deep.
| Program | RS4K - Science Book 2 — Astronomy |
| Publisher | Gravitas Publications Inc. |
| Author | Rebecca Woodbury, Ph.D., M.Ed. |
| Grade Band | Grades 2-4 |
Verdict: ✓ Recommended — Deep. Foundation_calc 100.0%, deep tier. Practices 92.9% green (book-wide score). Zero map errors. Zero confirmed FSEs.
Strict atomic-foundation scoring. The Astronomy quarter of Book 2 (Chapters 18-21) uses the atoms-and-molecules framework established in Ch 5’s universal claim as the explanatory anchor. Adjusted Gap 0.0%, Map Error 0.0%.
Chapters 18-21 cover telescopes (optical mechanism via lenses), constellations, planets in the habitable zone, and exoplanet detection via stellar wobble. Quantitative orbital periods. Greenhouse effect at K-2 — CO2 in atmosphere holds heat. Habitable zone reasoning at K-2 with counterfactual framing. Gravity correctly framed as a causal force in orbital and exoplanet contexts.
"Greenhouse effect at K-2: CO2 in atmosphere holds heat. Causal mechanism named." (Ch 19)
"Quantitative orbital periods — planets compared by their year length in Earth days." (Ch 20)
"Habitable zone reasoning at K-2 with counterfactual framing." (Ch 20)
"Exoplanet detection via stellar wobble — real physics at K-2. Gravity correctly framed as the causal force." (Ch 21)
FSE_CONFIRMED: 0. No factual science errors found.
Map errors: 0. No OAO error (REI-substance, REI-agent, LAE, AEC all zero).
Practices: 92.9% green. Six of seven NGSS scientific practices PRESENT; argument-from-evidence is PARTIAL. Every chapter operationalizes the full arc (question → hypothesis → experiment → data → conclusion). RATATAZ Experiment series provides hands-on investigations. The practices score is computed book-wide and applies identically to all five subject entries.
Ch 19 greenhouse effect could add a one-sentence note about CO2 molecules absorbing and re-emitting infrared light. Not required for the Recommended Deep verdict.
The five RS4K Book 2 subject entries (Chemistry, Biology, Physics, Geology, Astronomy) all share Foundation 100%, Adjusted Gap 0.0%, Map Error 0.0%, Practices 92.9% — the curriculum’s architecture is uniform across subjects because Chemistry establishes the universal atomic claim that every other subject uses.
| Total Passages Scored | 11 |
| Raw Gap Error | 0.0% (8 mechanism passages — all anchored at atoms-and-molecules level) FALSE = atoms/molecules not present before students are asked to explain. The student is navigating without a starting point. |
| Adjusted Gap Error | 0.0% (0 UNSCAFFOLDED — atomic foundation established in Chemistry quarter, used throughout) UNSCAFFOLDED = no atomic grounding at all. LESSON_ATOMS = atoms mentioned elsewhere in lesson but not connected to this concept. |
| Substance-Model Errors (REI) | 0 Curriculum treats a process or outcome as a substance - "heat flows," "energy is stored," "electricity flows like water." Student builds a substance ontology. |
| Label-as-Explanation (LAE) | 0 Curriculum provides a name and treats it as an explanation - "this happens because of gravity." Student believes knowing the name IS understanding the concept. |
| Vague-Entity Errors (AEC) | 0 Curriculum uses vague entities ("tiny particles," "building blocks") without specifying atoms or molecules. Student invents their own model with macroscopic properties. |
| Factual Science Errors (FSE) | 0 Statements that are scientifically incorrect - not imprecise framing, but wrong. Any confirmed FSE = Not Recommended. |
| Practices | 92.9% - Deep Seven practices scored PRESENT, PARTIAL, or ABSENT and averaged: asking questions, developing and using models, planning and carrying out investigations, analyzing and interpreting data, using mathematics, constructing explanations and designing solutions, and argument from evidence. Higher is better, the opposite direction from gap and map errors. Reported but not part of the Foundation Score or the verdict. |
Telescopes, orbits, habitable zone, exoplanets all framed at appropriate scale. Scaffolded by Ch 5 atomic claim and Ch 17 air-as-molecules framing. Greenhouse effect named as causal CO2 mechanism.
Atomic foundation established in Chemistry (Ch 2-5) used throughout the Astronomy quarter. Telescopes, orbits, habitable zone, exoplanets all framed at appropriate scale. Scaffolded by Ch 5 atomic claim and Ch 17 air-as-molecules framing. Greenhouse effect named as causal CO2 mechanism. Practices 92.9% green (book-wide).
Recommended (Deep) — Deep by design -
Evidence for every entry is published at three levels. Each level states what it contains and what it leaves out.
Scores, verdict, and the full pattern count for this unit are above: adjusted gap, REI / LAE / AEC counts, FSE status, and the seven-practice score. Passage-level detail for this unit is carried in the downloadable evidence file.
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