OpenSciEd Elementary - Grade 3, Unit 3.1: How can we design objects to balance and move in different ways?

Verdict and Foundation

OpenSciEd Elementary Unit 3.1 scores Foundation 0% - at the framework floor, identical to Units 1.1 and 2.2. Zero map errors across 30 student-facing passages. Zero confirmed FSEs after rigorous review. The adjusted gap is 100% - all 15 mechanism passages are UNSCAFFOLDED because the unit contains no atomic, molecular, or particulate content. This is explicit author intent. The "About the Science" section limits the unit's magnetism teaching to "noticing patterns that magnetic forces have a strength and direction that depends on magnets' material, size, and orientation to one another." The electron-spin explanation for ferromagnetism is not introduced. Other explicit deferrals: deformation → Unit 4.1; force pairs → middle school; electric charge → "until students learn about electrical charges, they cannot fully explain how electrical forces work at a distance."

Practices score 92.9% green - high, matching OpenSciEd 1.1, 2.2. OpenSciEd's pattern is now three-for-three confirmed across three grade levels and three subject areas (Grade 1 light, Grade 2 matter/engineering, Grade 3 forces/magnets): consistent strong inquiry pedagogy + consistent floor-level Foundation.

What Students Learn

The unit is organized around two anchoring phenomena: in Lesson Set 1 (Lessons 1-8), students investigate balance sculptures and kinetic sculptures. In Lesson Set 2 (Lessons 9-14), they re-anchor with magnetic sculptures.

Lessons 1-8 (Balance and Motion): Students notice and wonder about sculptures and build a Driving Question Board. Lessons 2-4 investigate symmetric, asymmetric, and off-centered balance - equal weights at equal distances balance; unequal weights need unequal distances (lever principle, qualitatively). Lesson 5 introduces balanced forces ("equal force pulling up at the balance point that opposes the force pulling down from the sculpture's weight"). Lessons 6-7 add unbalanced forces as causes of motion change plus the contact force concept. Lesson 8 is a synthesis art exhibit.

Lessons 9-14 (Magnetic Sculptures): Lesson 9 re-anchors with magnetic sculptures. Lesson 10 investigates magnets - they apply forces without touching, like poles repel and unlike attract. Lesson 11 tests magnet strength and distance with fair tests. Lesson 12 tests magnets with metal objects (some metals attract, others don't). Lesson 13 is an engineering design challenge: build a magnetic sculpture. Lesson 14 applies magnet ideas to adaptive clothing for accessibility.

Key Evidence

"3-PS2-3: Ask questions to determine cause and effect relationships of electric or magnetic interactions between two objects not in contact with each other. 3-PS2-4: Define a simple design problem that can be solved by applying scientific ideas about magnets." (Unit Overview, p. 13)

The NGSS bundle - all standards target observable forces.

"Their learning is limited to identifying that magnets have a special ability to exert forces without touching and is also limited to noticing patterns that magnetic forces have a strength and direction that depends on magnets' material, size, and orientation to one another." (About the Science, p. 37)

The cleanest single statement of the unit's atomic-deferral choice. Magnetism explicitly treated as pattern-level only.

"Until students learn about electrical charges, they cannot fully explain how electrical forces work at a distance." (About the Science, p. 37)

Explicit deferral of electric charge (and by extension, the electron-level explanation of magnetism).

"Balanced forces are the same strength but in opposite directions, so they have no effect on the motion. A change in motion is a result of an unbalanced force. When one thing touches another thing, it is applying a contact force." (Lesson 7)

Qualitative Newton's 1st/2nd Laws + contact force concept. Macroscopic mechanism.

"The magnets apply forces on one another without touching. These forces can pull toward each other or push apart. Like sides push apart, unlike sides pull together. If we flip one of the magnets, the forces change direction." (Lesson 10)

Magnetism as observable forces. Same NGSS standard, described at macroscopic level without atomic grounding.

"Stronger magnets cause a stronger force; weaker magnets cause a weaker force. A shorter distance between magnets causes a stronger force; a longer distance between magnets causes a weaker force." (Lesson 11)

Qualitative inverse-distance relationship. Correct K-3 physics.

"Apply ideas about magnets and forces to a new design challenge... Students learn about how magnets are used to make adaptive clothing, which helps people get dressed." (Lesson 14)

Equity-relevant engineering capstone - applying magnet ideas to design adaptive clothing for accessibility.

Practices

Practices: 92.9% (green tier - high). Six of seven NGSS practices are PRESENT; mathematics is PARTIAL. Distinctive strengths: (1) four Intentionally Developed Practices (Asking Questions, Developing Models, Constructing Explanations, Engaging in Argument); (2) Driving Question Board maintained across the entire 14-lesson arc; (3) cause-and-effect questioning scaffolded explicitly in Lesson 10; (4) force-arrow vector representation introduced at K-3; (5) two engineering design loops (balance sculpture art exhibit + magnetic adaptive clothing); (6) two Intentionally Developed Crosscutting Concepts (Patterns, Cause and Effect). Mathematics is PARTIAL by NGSS-aligned design.

What Would Change This Verdict

Option A (lift to Rewrite, ~30-50%): Add one teacher's note in Lesson 5 or 7 EXPLAIN: "Everything in the world is made of tiny pieces called atoms. Atoms push and pull on each other through forces - the same kinds of forces we're investigating with our sculptures. The contact forces we feel are actually atoms pushing on other atoms."

Option B (lift to Conditional, ~60-70%): Add one teacher's note in Lesson 10 explaining ferromagnetism : "Magnets work because of tiny particles inside the metal called electrons. In iron and a few other metals, the electrons mostly spin the same way, and that creates the magnet's pull."

Option C (push to Recommended, ~80%+): Restructure Lesson 5's force discussion to include "atoms exert forces on each other"; restructure Lesson 10 to include the electron-spin model of ferromagnetism explicitly.