Why Reading Gaps Keep Growing

What Schools Miss About MTSS, Diagnostics, and Splinter Skills

There is one pattern schools across the country know all too well: A student starts slightly behind in reading. Then stays behind. Then falls further behind. Then eventually becomes “significantly below benchmark.” Then receives more intervention. But somehow… still doesn’t catch up. By that point, many schools assume one of three things:

• the student has a deeper disability,
• the intervention “isn’t working,”
• or the gap is simply too large to close quickly.

But here is the truth most schools need to hear: Reading gaps rarely grow because of one big problem. They grow because of small problems schools fail to catch early. That is the real issue.

Many students do not fail in reading because they “can’t read.” They fail because they are missing specific discreet, splintered subskills that make fluent, accurate reading impossible. And when schools do not identify those subskills precisely, they provide support that feels helpful—but does not actually change outcomes. That is why gaps keep growing. Not because educators do not care. But because too many systems are still built to identify who is behind, rather than why they are behind. And those are not the same thing.

The MTSS Mistake That Keeps Schools Stuck

MTSS is supposed to help schools identify students early, provide support quickly, and prevent long-term reading failure. In theory, it should be one of the most powerful equity tools schools have. But in practice, many MTSS systems are too broad, too slow, or too surface-level to actually close reading gaps. Here is the common pattern:

Step 1: A universal screener identifies a student as below benchmark.

Step 2: The student is placed into intervention.

Step 3: The intervention is based on a general category:

• “phonics”
• “fluency”
• “comprehension”
• or “Tier 2 support”

Step 4: Weeks pass.

Step 5: Progress is minimal.

Step 6: The student gets referred for more support.

That cycle happens in schools every day.

And here is the problem: Screening tells you who needs help. It does not tell you exactly what to teach.

That distinction changes everything. The Institute of Education Sciences has long emphasized that effective early reading support requires schools to screen early and follow screening with targeted, evidence-based instruction matched to student need. Screening alone is not sufficient. Schools must connect data to explicit instructional response.

That is where many schools lose momentum. Because they stop at the flag. Instead of digging into the cause.

What Are “Splinter Skills” in Reading?

This is one of the most important concepts schools need to understand if they truly want to close reading gaps. Splinter skills are the small, specific reading subskills a student has not yet mastered—even when broader data categories make it look like they are “sort of okay.” This is why some students confuse educators.

For example:

A student may:

• know letter names
• but not retrieve sounds automatically

A student may:

• segment phonemes
• but not blend them quickly

A student may:

• decode in isolation
• but collapse in connected text

A student may:

• read words accurately
• but not fluently enough for comprehension

A student may:

• read CVC words
• but break down with digraphs, blends, vowel teams, or multisyllabic words

A student may:

• score “somewhat okay” on a broad screener
• but still have fragile foundational architecture

And that is exactly why reading gaps grow.

Because broad performance categories often hide the micro-skills that are slowing the student down every single day. That is the aha moment many schools need: Students don’t always fail because they’re missing “reading.”

They fail because they’re missing pieces of reading. And if those pieces are not identified and taught directly, the student never gets fully unstuck.

Why Universal Screeners Are Necessary—But Not Enough

Let’s be clear: Universal screening is essential. Schools absolutely should screen all students early and regularly to identify risk. Tools like Acadience and other validated screeners are powerful because they help schools see patterns in:

• phonemic awareness
• alphabetic principle
• nonsense word fluency
• oral reading fluency
• benchmark risk

That is critical.

But screening should be the beginning of decision-making, not the end of it. When schools only use universal screening data, they often make one of two mistakes:

Mistake #1:

They overgeneralize the problem.

Example:
“This student is low in ORF.”

But ORF is not the real root issue.
ORF is the symptom.

The real issue might be:

• weak blending
• fragile decoding automaticity
• poor orthographic mapping
• inconsistent vowel recognition
• weak phrasing
• low connected text stamina

Mistake #2:

They intervene too broadly.

Example:
“This student needs more fluency.”

But what kind of fluency support? If a student cannot read vowel teams or r-controlled vowels automatically, then repeated reading alone will not solve the issue.

The National Center on Improving Literacy continues to emphasize the importance of using multiple data sources and skill-specific assessment to identify the precise nature of reading difficulty, especially for students at risk for dyslexia or persistent reading failure. (improvingliteracy.org)

That means schools need to move from: broad category intervention to precision intervention

That is where real growth happens.

The Missing Link: Diagnostic Reading Assessment

If screening identifies risk, then diagnostics identify instructional truth. And too many schools skip that step. A high-functioning MTSS system does not just ask:

• Is the student below benchmark?

It asks:

• Which exact skill is fragile?
• Which exact skill is inconsistent?
• Which exact skill is missing?
• Which exact skill is preventing fluency and comprehension?

That means schools need diagnostic tools and teacher practices that help uncover whether the student is struggling with:

• phonological awareness
• phoneme manipulation
• sound-symbol mapping
• letter-sound automaticity
• continuous blending
• word chaining
• orthographic mapping
• high-frequency word retrieval
• connected text transfer
• phrasing
• syntax or language comprehension
• morphology
• multisyllabic word reading

That is what strong literacy systems do. They do not simply identify that a child is struggling. They identify what the child is struggling with inside the larger reading process. And that is what makes intervention actually effective.

Why Some Reading Interventions Fail

This is another hard truth schools need to hear: Many reading interventions fail not because intervention is bad… but because the instruction is too generic for the student’s actual gap.

That is especially true in schools where students are grouped by:

• broad level
• general benchmark band
• convenience
• staffing limitations
• or schedule availability

Instead of by actual skill need.

For example:

A group labeled “below benchmark” may include students who need:

• phoneme segmentation
• short vowel automaticity
• digraph decoding
• connected text fluency
• multisyllabic decoding
• oral language support

That is not one group. That is five different instructional problems sitting at one table. And when that happens, the intervention becomes diluted. Students get exposure. But not acceleration.

That is why schools must stop thinking of intervention as: “extra help” and start thinking of it as: “targeted skill repair”

That mindset shift is everything.

What Strong MTSS Systems Actually Do Differently

Schools that close reading gaps faster tend to have several things in common.

1. They screen early and frequently.

They do not wait until students are deeply behind.

2. They use diagnostics immediately.

They do not assume the screener told the whole story.

3. They group students by skill.

Not by label. Not by generic reading level.

4. They progress monitor the actual skill being taught.

Not just broad reading performance.

5. They adjust fast.

They do not leave students in stagnant interventions for months.

This is where schools often experience another aha moment:

MTSS is not just a tiered service structure.

It is a decision-making system. And if the decisions are not precise, the tiers will not produce results.

That is why leadership matters so much. Because schools do not close reading gaps through programs alone. They close them through strong instructional decision-making.

What This Means for Students with IEPs, ELLs, and MLLs

This conversation becomes even more important when we are talking about students who are historically underserved in literacy systems.

For:

• students with IEPs,
• English Language Learners,
• Multilingual Learners,
• students with dyslexia,
• and students with interrupted literacy development…

schools must be especially careful not to overgeneralize their reading needs.

Because these students are often misunderstood through broad categories like:

• “language issue”
• “processing issue”
• “special education”
• “low reader”

But broad categories do not teach children to read.

Specific instruction does.

That means students need schools to identify whether the issue is:

• decoding
• language
• phonology
• orthography
• automaticity
• comprehension
• or some combination of several interacting skill gaps

When schools get that right, outcomes change dramatically.

When they do not, gaps widen.

The Bottom Line

Reading gaps keep growing because too many systems are still built to identify risk without fully identifying cause. And if schools want to truly narrow and close achievement gaps in reading, they must build MTSS systems that are:

• early
• precise
• diagnostic
• responsive
• and instructionally aligned

Because the fastest way to lose a struggling reader is to give them support that sounds good but does not actually match the skill they need. And the fastest way to accelerate a struggling reader is to identify the exact skill that is broken—and teach it with urgency, clarity, and repetition. That is how schools stop managing reading gaps…and start closing them.

Research & References

• Institute of Education Sciences. Foundational Skills to Support Reading for Understanding in Kindergarten Through 3rd Grade. (ies.ed.gov)
• National Center on Improving Literacy. Defining Dyslexia. (improvingliteracy.org)
• National Center on Improving Literacy. Literacy Instruction & Intervention Resources. (improvingliteracy.org)
• National Center on Intensive Intervention. Academic Intervention Tools Chart. (intensiveintervention.org)
• National Center on Intensive Intervention. Data-Based Individualization. (intensiveintervention.org)