100% gap with a complete particle model that never names the entity. 18 investigations build particles with weight, volume, and motion to explain dissolving, evaporation, condensation, and freezing — but “particle” is never defined as atom or molecule. Explicitly defers atomic terminology. 100% practices. One sentence from the fix.
| Program | The Inquiry Project — Investigating Water Transformations |
| Lesson Title | Grade 5C — 18 investigations across 5 sections |
| Publisher | TERC (Cambridge, MA) |
| Author | TERC Research Team |
| Grade Band | Grade 5 (3-5 calibration) |
Foundation Score: 0.0%. Eighteen investigations build a complete particle model of matter — particles with weight, volume, motion, bonding, and arrangement differences across states — without ever naming the particles as atoms or molecules. Gap error: 100.0%. Map error: 42.9% (15 AEC from systematic use of “particles” without atomic anchor). Zero factual errors. The curriculum explicitly states: “Without using the terms molecules or atoms.” At Grade 5, the end of the 3-5 band, this produces a 100% gap.
Eighteen investigations across five sections: Water, a Liquid (mini-lakes, weight/volume, dissolving with weight conservation), Water to Vapor (evaporation, 2-bottle closed system, condensation), Water to Ice (ice vs water, weight/volume during freezing, computer particle model), Air, a Gas (air has weight, air takes up space, compressibility through particle spacing), and Two Scales (connecting macroscopic to particle-level).
Students build a particle model that explains dissolving, evaporating, condensing, freezing, and melting — and they never learn what the particles are called. The student notebook has zero “atom” and zero “molecule” — only “particle” (18 occurrences). The teacher guide has 40 “molecule” and 10 “atom” in Scientist’s Essays — all teacher-only.
What we found: 25 mechanism passages scored. Zero name atomic-level entities. 100% gap — no scaffolding credit possible because there are no TRUE passages anywhere. 15 AEC errors from systematic use of “particles” without atomic anchor.
“In ice, particles are locked together, even when they vibrate, and hold their shape. In water, particles slide past and collide with one another, and take the shape of its container.” — Investigation 12
Correct molecular behavior described without the word “molecule.” The mechanism is right. The entity is unnamed.
“Matter is composed of particles that have weight, occupy space, and are too small to see.” — Section 1
Core particle claim. “Particles” could be “molecules” — and the mechanism would be anchored.
“Without using the terms molecules or atoms, this curriculum unit provides students with a set of experiences that helps them develop the understanding that particles too small to see can have weight, take up space.” — Overview
The design choice is explicit and documented. The curriculum knows what it is deferring.
“We will not get to the atomic model in the present curriculum, but we are laying the foundation.” — Scientist’s Essay
And from the same essay: “Those fundamental particles — molecules — can be further broken down into yet smaller entities — atoms.” The teacher guide has the answer. Students do not.
Map errors: 15 AEC. Every passage using “particles” to explain mechanism without defining them as atoms or molecules scores AEC. No REI. No LAE. No FSE. The particle model IS mechanism — labels are not substituted for explanation.
FSE: 0. All science content is factually correct. The particle model descriptions accurately describe molecular behavior.
Practices: 100.0% — Deep (3-5 calibration). Six PRESENT, zero PARTIAL, one N/A (engineering design). Core strengths: 2-bottle closed system as student-designed investigation, computer particle model for phase changes, annotated drawings of particle arrangements, Two Scales framework connecting macroscopic to particle-level, Concept Cartoons for argumentation, and rigorous quantitative data collection across all transformations.
Replace “particles” with “molecules” throughout the student materials. The particle model is already structurally correct: particles locked together in solids, sliding in liquids, spreading in gases. The mechanism is taught. The measurements are rigorous. The computer model shows the right behavior. The only missing piece is telling students that the particles they have been studying are called molecules, and that molecules are made of atoms. The fix is a vocabulary change, not a structural one.
| Total Passages Scored | 35 |
| Raw Gap Error | 100.0% (25 of 25 mechanism passages FALSE) FALSE = atoms/molecules not present before students are asked to explain. The student is navigating without a starting point. |
| Adjusted Gap Error | 100.0% (25 UNSCAFFOLDED FALSE; 0 SCAFFOLDED) 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) | 15 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) | 1 flagged for review - Weight vs mass: "particles that have weight" should be "particles that have mass." Three years of measurement and conservation reasoning built on weight instead of mass. Especially problematic at Grade 5 where the particle model is being formalized. Statements that are scientifically incorrect - not imprecise framing, but wrong. Any confirmed FSE = Not Recommended. |
| Practices | 100.0% - 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. |
18 investigations build a complete particle model — particles with weight, volume, motion, bonding, and arrangement differences across states — without ever naming the particles as atoms or molecules. Explicit design note: "Without using the terms molecules or atoms." 100% gap, 15 AEC map errors, 0 FSE. The mechanism is taught; the name is withheld.
Complete particle model with computer simulations, annotated drawings, and two-scales reasoning. 100% practices. 2-bottle closed system as student-designed investigation. Conservation reasoning through particle persistence. The particle model is structurally sound and mechanistically correct — one word away from the fix.
Final unit in the 3-year progression. Grade 3C (0 map errors, 83.3% practices) builds measurement. Grade 4C (0 map errors, 91.7% practices) adds density and conservation. Grade 5C introduces the particle model (15 AEC errors, 100% practices) but never names particles as atoms or molecules. The progression builds everything except the name. Practices improve from 83.3% to 91.7% to 100% across the three years.
shallow by design - Design overview states: "Without using the terms molecules or atoms, this curriculum unit provides students with a set of experiences..." Scientist’s Essay confirms: "We will not get to the atomic model in the present curriculum, but we are laying the foundation." The deferral is explicit, documented, and defended.
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 4 passages verbatim from the curriculum.
This file covers the unit scored on this page.
The complete classified evidence table for this unit, every extracted passage with its classification, is available to researchers, journalists, and to the publisher of the program being scored. This is a standing offer with no conditions attached and no agreement to sign.
If you think a score is wrong, say so. Challenges and our responses to them are published on the evidence and challenges page, including the ones we lose.
Have a curriculum, kit, or program you'd like us to review? Drop us a note, tell us what you want to see, we'll test it and post the results.