The SOLID Framework

Built to help students understand, and to keep it.

A model for designing science units that draw on the whole of what we know about how people learn: how understanding is built, and whether it lasts.

Science of Learning Instructional Design · Victor Sampson, The University of Texas at Austin

Read the white paper
The premise

Two jobs, not one

A student can figure something out beautifully in the moment and still lose most of it a few months later. That is not a sign the teaching went wrong. It is a sign the unit was built to help students understand an idea, but not to help that understanding last.
Building understanding

Meaning-making and coherence

Starting from what students already think, giving them a reason to care, letting them reason together, and helping them construct an idea that hangs together from their point of view. Science teaching has gotten genuinely good at this.
Making it last

Consolidation and stabilization

Bringing an idea back after it is built, having students rebuild it from memory rather than reread it, practicing it in more than one setting, and using assessment to find and repair the soft spots before they harden. This half has shaped how we build units far less.

Both come from the same place. SOLID is built to honor both from the start, so the same unit that helps students build understanding also helps that understanding endure.

A SOLID unit at a glance

A deliberate loop, not a straight line

A unit is not a collection of lessons but a sequence in which each stage does a distinct job. It opens and closes with the same assessment structure, and the work between is arranged so ideas are constructed, consolidated, checked, and stabilized in turn.

Diagram: The flow of a SOLID unit: a formative Phenomenon-Driven Task™ opens the unit and a summative one closes it. Between them, a Meaning-Making and Coherence-Building phase (a three-dimensional Investigation or Design Challenge as the core, with a Procedural Fluency lesson and a Conceptual Foundation lesson) is followed by a Consolidation and Stabilization phase (Vocabulary Development and Review, an educative Phenomenon-Driven Task™, and data-driven Targeted Growth Stations with Refinement and Enrichment pathways).
Figure 1. The flow of a SOLID unit. A formative Phenomenon-Driven Task™ opens the unit and a summative one closes it. Between them sit two phases: Meaning-Making and Coherence-Building, then Consolidation and Stabilization.

A three-dimensional investigation sits at the center as the integrative core, the experience that does a little of almost everything. Because it does a little of everything, it masters nothing on its own, so each other lesson picks up a single job the core can only touch, and carries it toward mastery.

Why each component exists

A small team of lessons, each with one job

No single learning experience can carry everything the two jobs require. The fix is not a better single lesson; it is a team of lesson types, each responsible for one job, arranged so together they cover the whole field. Examples below come from one eighth-grade unit on the properties and changes of matter.
1 · THE INTEGRATIVE CORE

Investigation or Design Challenge

Students confront a phenomenon, propose an explanation, plan and run an investigation, analyze data, and build a written argument from evidence. Authentic inquiry naturally recruits prior knowledge, motivation, collaborative reasoning, and argument at once. In this unit: students figure out what happens to the total mass of a closed system when three substances react inside it.
2 · FOCUS ON MEANING & STRUCTURE

Conceptual Foundation Lesson

Students move from an individual model, to a small-group model, to a gallery of other groups' models, to a revised model, and finally to the account the scientific community would offer. The revision step is where the lesson turns. In this unit: students model what happens to atoms during a chemical reaction, using spheres to represent atoms.
3 · FOCUS ON DURABILITY

Procedural Fluency Lesson

Built almost entirely from the consolidation evidence. A worked example is paired with the target procedure, support is faded to independent practice, students diagnose errors, and the lesson closes with self-paced retrieval on a ramp of difficulty. In this unit: students identify atoms on each side of an equation and determine whether mass is conserved, practicing on problems labeled mild, medium, and spicy.
4 · FOCUS ON KNOWLEDGE STRUCTURE

Vocabulary Development & Review

Late in the unit, students map every key term into one representation of terms, pictures, and labeled linking words, first alone, then as a group, then alone again. The named links are the heart of it: a link a student must name forces a relationship into the open. In this unit: terms from element and compound to conservation of mass, coefficient, and subscript are pulled into one connected map.
5 · FOCUS ON SPACING & ASSESSMENT AS LEARNING

Phenomenon-Driven Task™ Thread

The same task appears three times, varying only its phenomenon: formative before instruction, educative at the midpoint, summative at the end. What looks like repetition is the unit's principal mechanism for endurance, because ideas are retrieved on occasions separated in time. In this unit: students classify observable changes in matter and explain their reasoning, three times, each with a fresh phenomenon.
6 · FOCUS ON RESPONDING TO ASSESSMENT

Targeted Growth Stations

Self-checking stations reteach the specific ideas the educative task brought into view, split into Refinement (a further pass) and Enrichment (extension). Stations are selected by the data, not assigned by a label, which is what makes this a response to assessment. In this unit: a Refinement station retargets identifying atoms on each side of an equation; an Enrichment station reaches toward a new context.
The warrant

Ten principles of learning

Drawn from How People Learn II (NASEM, 2018), which gives the findings about memory, retrieval, and transfer the same authoritative standing it gives prior knowledge, motivation, and social interaction. Each principle is paired with the design decision it asks of a unit.

Building understanding

How understanding is constructed and made coherent.

  • 1. People interpret new information through ideas they already hold. Elicit students' current ideas first, then build forward from them.
  • 2. Culture shapes what a community treats as useful or acceptable. Help students grow into the standards of the scientific community.
  • 3. People reason through interaction with others and with shared representations. Make talk and the refinement of representations the engine of the work.
  • 4. Motivation is a condition the work must create, not a trait students bring. Give students a genuine reason to take up a new idea.
  • 5. Self-regulation brings coherence to a developing body of ideas. Build in occasions to monitor understanding and set goals from it.

Making it last

Whether understanding endures and stays usable.

  • 6. Feedback is how a learner monitors an evolving understanding. Embed assessment for learning inside the work itself.
  • 7. The ideas a learner retains are those that prove useful. Give occasions to apply an idea beyond where it was first learned.
  • 8. Memory is reconstructed, not played back. Space the reconstruction of core ideas across occasions separated in time.
  • 9. Memory is context-dependent and shaped by the cues present at recall. Practice reconstruction across varied contexts and cues.
  • 10. Ideas are easier to use when organized around a few core concepts. Have students build representations of organized, connected knowledge.
Coverage at a glance

Which component carries which principle

Every principle has at least one strong carrier, with the single exception of transfer, the unit's open frontier. And the five consolidation principles are carried most strongly by exactly the components with no close equivalent in current meaning-making practice. That alignment is the heart of the matter.

  • 1. Build from prior knowledge Strong: Investigation / Design, Conceptual Foundation, PDT Thread. Partial: Procedural Fluency, Vocabulary Dev. & Review, Targeted Growth Stations.
  • 2. Culture & community standards Strong: Investigation / Design, Conceptual Foundation. Partial: Procedural Fluency, Vocabulary Dev. & Review, Targeted Growth Stations. —: PDT Thread.
  • 3. Interaction & refinement Strong: Investigation / Design, Conceptual Foundation, Procedural Fluency, Vocabulary Dev. & Review, Targeted Growth Stations. —: PDT Thread.
  • 4. Motivation Strong: Investigation / Design, Targeted Growth Stations. Partial: Conceptual Foundation, Procedural Fluency, PDT Thread. —: Vocabulary Dev. & Review.
  • 5. Self-regulation Strong: Investigation / Design, Procedural Fluency, Targeted Growth Stations. Partial: Conceptual Foundation, Vocabulary Dev. & Review, PDT Thread.
  • 6. Assessment as feedback Strong: Investigation / Design, PDT Thread, Targeted Growth Stations. Partial: Conceptual Foundation, Procedural Fluency. —: Vocabulary Dev. & Review.
  • 7. Transfer (usefulness) Near: Investigation / Design, Procedural Fluency, PDT Thread, Targeted Growth Stations. —: Conceptual Foundation, Vocabulary Dev. & Review.
  • 8. Reconstruction over time (spacing) Strong: Conceptual Foundation, Procedural Fluency, PDT Thread, Targeted Growth Stations. Partial: Investigation / Design, Vocabulary Dev. & Review.
  • 9. Context-dependent reconstruction Strong: Procedural Fluency, PDT Thread. Partial: Investigation / Design, Conceptual Foundation, Vocabulary Dev. & Review, Targeted Growth Stations.
  • 10. Organized, connected knowledge Strong: Conceptual Foundation, Vocabulary Dev. & Review. Partial: Investigation / Design, Procedural Fluency, PDT Thread, Targeted Growth Stations.

Strong primary, deliberate carrier · Partial meaningful secondary contribution · Near engineered near- or mid-range transfer · — not built to serve this principle

The one honest limit

Far transfer lives above the unit

The model builds deliberately for near and mid-range transfer. Far transfer, applying an idea in a genuinely different domain, requires two domains to occur at all, and a single unit contains only one. The opportunity therefore lives at the scale of the course: because the same practices and crosscutting concepts recur, every later unit is a second domain into which an earlier unit's core ideas can be pulled forward. Named not as a concession, but as an invitation.
Endurance and equity

Designing for endurance is designing for fairness

A student with time, help, and materials at home can reconstruct a fragile idea after the unit moves on. A student without those resources cannot, and is left to depend on whatever the classroom itself made durable. Building consolidation into the unit, rather than leaving it to be supplied afterward, distributes the benefit of instruction most widely to the students least able to supplement it elsewhere.
What this means for you

One model, read three ways

For teachers

A clear job for every lesson

The effort you already invest in helping students make sense of phenomena is joined by lessons designed to make that understanding last. The task thread and growth stations tell you, before the summative measure, exactly which ideas still need attention and for whom.
For curriculum leaders

A coverage checklist

Ask not only whether a unit anchors in a phenomenon and builds coherence, which strong materials already do, but whether it spaces the reconstruction of core ideas, varies the cues, and diagnoses and reteaches before the summative. A unit can earn top marks and still leave learning fragile.
For materials designers

Endurance built in from the start

A way to realize the vision of the Framework that builds endurance into a unit rather than leaving it for teachers to supply afterward. The diagnose, reteach, remeasure logic is built into the architecture of a unit rather than added around its edges.

Our Texas science curriculum is built on SOLID

Coming soon · K–12 Texas

ADI Science for Texas, grades K through 12, is designed on the SOLID framework from the ground up, so the same units that help students build understanding are built to make it last. We are opening a limited group of pilot classrooms and districts ahead of the full release. Add your name to help shape it and be first in line.

Grade bands and start dates are firming up. We will reach out with pilot details.

    Apply to pilot

    Read the white paper

    The full framework, its warrant across five consensus reports, the coverage analysis, and a worked eighth-grade example, in one document.

    Suggested citation. Sampson, V. (2026). Designing instructional materials for coherence and endurance: Why science units should be built to help students both build understanding and keep it [White paper]. The University of Texas at Austin.

    Also written up for practitioners

    • Why One Great Lesson Is Never Enough · Middle school science, matter · In review · coming soon
    • Designing Biology Units That Make Learning Last · High school biology, the cell · In review · coming soon
    • The SOLID unit structure in ADI curriculum · The model realized across the ADI Science units