OpenSciEd Elem 2.2 (Grade 2 matter/engineering unit) - second OpenSciEd unit confirming pattern: 92.9% practices (high) + 0% Foundation (Not Recommended floor). Full engineering integration: students interview kindergartners, design toys, present to real audience.
| Program | OpenSciEd Elementary |
| Unit | Grade 2, Unit 2.2: How can we design a new toy? |
| Publisher | OpenSciEd |
| Author | OpenSciEd Curriculum Development Team |
| Grade Band | Grade 2 (K-2 calibration applied) |
| NGSS Alignment | 2-PS1-1, 2-PS1-2, 2-PS1-3, 2-PS1-4, K-2-ETS1-1, K-2-ETS1-2, K-2-ETS1-3 |
OpenSciEd Elementary Unit 2.2 scores Foundation 0% - at the framework floor, identical to Unit 1.1. Zero map errors across 30 student-facing passages. Zero confirmed FSEs after rigorous review. The adjusted gap is 100% - all 13 mechanism passages are UNSCAFFOLDED because the unit contains no atomic, molecular, or particulate content. This is explicit author intent. The "About the Science" section states the deferral directly: "This is foundational understanding for further learning in 5th grade about matter being made of particles that are too small to be seen." Two other explicit deferrals also appear: states of matter → Unit 2.3; energy concepts → not covered.
Practices score 92.9% green - high. OpenSciEd's program-wide pedagogical strength is confirmed: two units, same score (92.9% / 0%). The Grade 2 unit adds full engineering design integration (K-2-ETS1-1, 2, 3) - students interview kindergartners as authentic stakeholders, design and build toys, gather peer feedback, present final products to a real audience.
A direct comparison is with ACS Inquiry in Action Chapter 6, which covers the same NGSS bundle (2-PS1-1, 2, 3, 4) but goes atoms-first. ACS Ch 6 scored Foundation 100%; OpenSciEd 2.2 scored Foundation 0%. Same standards, opposite atomic choice, opposite Foundation scores. This is a clear demonstration that the structural decision to teach atoms at K-2 is available within NGSS and produces dramatically different framework outcomes.
The unit is organized around an engineering design problem: 2nd-grade students design and build a new toy for their classroom, then a new toy for kindergartners after interviewing them as users. Material properties are investigated as a means to support good engineering choices.
Lessons 1-3 establish materials investigation. Students start with a book about toys from around the world, then plan and conduct investigations of material properties using vocabulary like flexible, strength, texture. Lesson 3 sorts materials by properties using class data charts and connects properties to purposes. Lessons 4-6 cover changes to materials. Lesson 4 introduces disassembly/reassembly (NGSS 2-PS1-3). Lesson 5 observes a crayon melting (reversible) and a paper burning (irreversible), then sorts cards by reversibility (NGSS 2-PS1-4). Lesson 6 explicitly teaches engineering argumentation. Lessons 7-10 are the kindergartner toy design loop: interview kindergartners about their interests, build a toy, get peer feedback and revise, present the toy to the kindergartners.
The unit's central science model: materials have properties; properties suit different purposes; objects can be disassembled and reassembled; heating and cooling cause changes that are sometimes reversible (crayon) and sometimes not (paper). All four NGSS 2-PS1 PEs are delivered at the macroscopic level.
Unit targets 2-PS1-3 (evidence-based account of disassembly/reassembly from a small set of pieces) and 2-PS1-4 (reversible vs. irreversible changes from heating/cooling). (Unit Overview, p. 13)
All four NGSS 2-PS1 PEs in one unit. Same bundle that ACS Inquiry in Action covers across Chapters 1-6.
"This is foundational understanding for further learning in 5th grade about matter being made of particles that are too small to be seen." (About the Science, p. 39)
The explicit deferral. The author note acknowledges that the disassembly/reassembly concept students are building (NGSS 2-PS1-3) connects to the particulate model - but the unit treats this as foundation for 5th grade rather than introducing the particulate model in Grade 2. ACS Ch 6 made the opposite choice with the same standard.
"This unit will not cover concepts related to energy." (Unit Overview, p. 19)
"This unit does not address, 'Different kinds of matter exist and many of them can be either solid or liquid, depending on temperature.'" (Unit Overview, p. 14)
Two more explicit deferrals: energy and states of matter both postponed.
"Materials have properties that serve particular purposes. We need to choose materials that have the properties we need for meeting the purpose of each part of our design." (Lesson 3)
Macroscopic properties-to-purposes mapping. The unit's central concept stays at the material scale throughout.
"Materials can be changed by heating and cooling. Some changes are reversible and some are not." (Lesson 5)
NGSS 2-PS1-4 delivered macroscopically. No molecular kinetic theory.
"Engineers use argumentation to figure things out and to explain their thinking." (Lesson 6)
Argumentation explicitly taught as engineering practice. Word Wall: "argumentation, claim, evidence."
"Interview kindergarten students. Develop a new toy design based on kindergartners' interests... Present the final toy to kindergartners." (Lessons 7, 10)
Authentic engineering with real user stakeholders - the strong engineering-design integration at K-2.
Practices: 92.9% (green tier - high, alongside OpenSciEd 1.1). Six of seven NGSS practices are PRESENT; mathematics is PARTIAL. Distinctive strengths: (1) full engineering design integration (the entire 10-lesson arc is an engineering loop with iterative model revision); (2) multi-stage modeling sequence (design sketches updated repeatedly across lessons); (3) authentic user research (kindergartner interviews); (4) argumentation as explicit practice (Lesson 6 dedicated book, Consensus Discussion structure, "argumentation/claim/evidence" on Word Wall). Four practices are tagged "Intentionally Developed" - more than most K-2 units.
The unit is correctly designed against NGSS 2-PS1 + K-2-ETS1. Changing the verdict would require adding atomic content the standards don't require.
Option A (lift to Rewrite, ~30-50% Foundation): Add one teacher's note to Lesson 4: "Everything we can disassemble and reassemble is made of tiny pieces. The biggest pieces are atoms - too small to see, but real. Different materials are made of different atoms in different arrangements. We'll learn more about atoms in 5th grade."
Option B (lift further): Add one sentence in Lesson 5 EXPLAIN: "Reversible changes happen because the tiny pieces (called molecules) just rearrange and can rearrange back. Irreversible changes happen because the pieces actually change into different pieces."
Option C (push to Recommended, ~80%+): Build a short Lesson 3.5 using the materials-pieces analogy explicitly (matching ACS Ch 6's Snap Cubes-as-atom-models approach).
All three options exist as templates in other programs reviewed curricula. None is necessary to satisfy NGSS 2-PS1.
| Total Passages Scored | 30 |
| Raw Gap Error | 100.0% (zero atomic content in unit) FALSE = atoms/molecules not present before students are asked to explain. The student is navigating without a starting point. |
| Adjusted Gap Error | 100.0% (all 13 mechanism passages UNSCAFFOLDED - explicit NGSS-aligned deferral of atoms to 5th grade) 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. |
OpenSciEd Elementary 2.2 confirms the program-wide pattern established by Unit 1.1: strong inquiry pedagogy (92.9% practices) + floor-level Foundation (0%). Both units cover NGSS 2-PS1-3 (object disassembly/reassembly). Both publishers deliver high-quality K-2 design. Same standards, opposite atomic choice, opposite Foundation scores.
Exemplary inquiry pedagogy. Full engineering design integration (3 K-2-ETS1 standards). Authentic user research (kindergartner interviews). Multi-stage modeling sequence (design sketch as iterative model). Argumentation as explicit K-2 practice. Four practices tagged "Intentionally Developed." Real engineering design loop with stakeholder feedback and final presentation to real audience.
shallow by design - Zero MISCONCEPTION_BY_DESIGN flags. The atomic deferral is structurally intentional (explicit "About the Science" note: foundational for 5th grade learning about particles). Three explicit deferrals all consistent with NGSS K-2 framing. No substance-model energy framings. No REI errors. Heating-cooling reversibility correctly distinguished at observational level.
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. The analysis quotes 8 passages verbatim from the curriculum.
This file covers the unit scored on this page.
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