The Science of Reading and Writing

What David Share’s Theory Can Teach Us about Writing: A Personal Look

I’ve been spending some time thinking about the science of reading and a theory from reading research that I find genuinely interesting: David Share’s work on the “Universal Theory” of learning to read. I want to be clear up front. This is not an endorsement, a claim of alignment, or a new research position for SRSD writing, but rather an exploration of the skills involved in reading development. It’s simply my professional curiosity as someone who spends every day thinking about how students learn about reading and writing.

That curiosity comes from a familiar place. When something works well in classrooms, I want to understand why. Not just at the surface level, but at the level of learning and cognition.

Share’s theory gave me one of those “this helps explain something I already see” moments, particularly in how it intersects with literacy development. For a detailed articulation of Share’s model of reading development, see Blueprint for a Universal Theory of Learning to Read: The Combinatorial Model, which describes how learners progress from decoding elements into fluent processing by combining and unitizing meaningful units across contexts.

A quick summary of Share’s idea

In simple terms, Share argues that learning to read isn’t just about memorizing words; it’s about developing a “self-teaching” mechanism. Students expand their vocabulary by combiningsmall, initially meaningless elements like letters or characters into meaningful units. Over time, this process becomes more efficient and automatic. Readers move from effortful decoding to fluent, independent reading through dedicated practice.

He describes this as a “combinatorial process,” kind of like a developmental “tree,” where learning and reading comprehension grow:

• vertically, from basic letter-sound units to more complex multisyllabic words, and
• outward, as knowledge becomes more refined and flexible.

This theory draws on decades of research across languages and writing systems, reflecting the science of reading principles and various educational theories. It helps explain why certain patterns of reading development are consistently observed, even across very different orthographies.

Importantly, this is a theoretical model, not an instructional program.

Why this caught my attention as someone who works with SRSD and writing

What struck me was not that Share’s theory “matches” SRSD, but that it helps explain comprehension and learning principles we already rely on with student writing.

In SRSD, we don’t overwhelm students with all the grammar rules or every possible way to write all at once. We teach a small number of powerful strategies and routines. Students practice them with support, then gradually internalize them. Over time, those strategies become tools students can use flexibly across writing tasks.

That pattern (small elements, deliberately taught, combined, and recombined over time) feels conceptually similar to what Share describes in reading development.

Again, this is not a theoretical claim. It’s an observation.

Where the Ideas Feel Aligned and What Educators Can Take from Them

From my perspective, the value in David Share’s theory is not that it “matches” SRSD, but that it helps explain learning principles that many effective instructional frameworks already rely on. When those principles show up across both reading theory and writing instruction, they are worth paying attention to.

1. Learning builds from small, teachable units

Share’s combinatorial model emphasizes that reading fluency develops as students learn to combine small, initially meaningless units into increasingly complex structures. Growth depends on teaching those units deliberately and giving learners opportunities to recombine them independently.

SRSD approaches writing in a similar way. Strategies, self-regulation routines, and explicit planning structures are not content to be memorized; they are tools students use to generate meaning. When we teach a student to use a graphic organizer or set a goal, we are giving them “units” of composition. For educators, the takeaway is this: instruction works best when we focus less on producing finished writing products and more on teaching students the component actions that allow them to produce meaning in their own writing.

2. Automaticity is a prerequisite for higher-level thinking

Share underscores that fluent reading and comprehension emerge only when lower-level processes, like decoding, become automatic, freeing cognitive resources for meaning-making. SRSD operates on the same assumption in writing. When students no longer struggle to remember what to do next, they can focus on ideas, organization, and audience.

For teachers, this reframes automaticity. It is not a reward for mastery or a skill students “pick up” on their own. It is an instructional outcome that must be deliberately supported. Practice, repetition, and explicit modeling are not remedial moves; they are essential conditions for independence.

3. Development is recursive, not linear

Neither Share’s work nor SRSD for writing assumes that literacy development moves in a straight line. Growth involves refinement, revisiting earlier skills, and applying them in new contexts. Earlier units of learning do not disappear; they are reorganized and reused in increasingly complex ways.

This matters for instructional decision-making. It normalizes revisiting foundational skills without framing that work as regression. It also explains why struggling readers and writers often need instruction that reconnects them to earlier units of learning, rather than simply more exposure to grade-level tasks.

Taken together, these shared principles point to an important instructional stance: explicit instruction and independence are not opposites. Teaching students how the system works, whether in reading or writing, enables them to operate independently within it.

Where the differences matter and why they matter

As much as I find these parallels exciting, the differences between Share’s theory and SRSD are just as important as the similarities.

SRSD is an instructional framework. Share’s work is not.

SRSD is supported by decades of writing intervention research, including experimental and quasi-experimental studies that examine instructional effects on student writing outcomes. Share’s theory does not test instruction. It explains learning.

That distinction matters. We should not treat learning theories as interchangeable with instructional evidence.

SRSD makes causal claims. Share’s theory does not.

SRSD research asks, “What happens when teachers teach writing this way?” Share’s work asks, “How does learning unfold over time?” Those are different scientific purposes.

SRSD is designed for classroom use. Share’s theory is explanatory.

Teachers can implement SRSD tomorrow to enhance their writing instruction. Share’s theory helps us think more clearly about why certain instructional choices make sense, but it does not tell teachers what to do.

Why I still find Share’s work validating

Even with those key differences, I find Share’s work validating. Not because it “proves” SRSD, but because it sits comfortably alongside it.

Good instructional frameworks tend to align with well-established learning principles. When a theory from the science of reading helps explain why explicit, strategic instruction supports independence and fluency, incorporating reading strategies, that’s reassuring. It suggests we’re not working against how learning happens, especially in writing.

I also think this kind of theoretical work helps bridge conversations between reading and writing. Teachers often experience these as separate worlds. Research like Share’s reminds us that literacy development, whether reading or writing, depends on cumulative learning, automaticity, and strategic control.

A final word of caution (and respect)

This is, of course, a professional opinion, not a formal position statement. SRSD does not require external theories to justify its effectiveness in the classroom. Its decades of peer-reviewed evidence on writing outcomes stand firmly on its own.

But as someone who cares deeply about teaching writing well, I appreciate thoughtful theories that help explain learning in ways that feel consistent with what we see in classrooms. Share’s work on the science of reading does that for me, as it is compared to the science of writing.

I’m impressed by the care of his thinking. I’m encouraged by how much it aligns with core learning principles. And I’m confident that keeping these ideas in dialogue, without blurring boundaries, only strengthens our understanding of reading and literacy instruction.

If you’re interested in exploring more about how these “reading-writing” bridges work in practice, I suggest these other blogs:

• Reading and Writing Relationships: What Decades of Research Reveal
• Reading Comprehension Strategies: How Writing Helps
• The Science of Writing: Integrating Reading and Writing for Enhanced Literacy
• Using Writing as a Tool for Improving Reading and Learning

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