Two Pathways to Identification: RTI vs. Pattern of Strengths and Weaknesses

This is Part 2 of a 5-part series on Specific Learning Disability identification under IDEA and Texas law.

Two evidence-based pathways lead to identifying a Specific Learning Disability (SLD): Response to Intervention (RTI) and the Pattern of Strengths and Weaknesses (PSW) model. Both are designed to help students reach educational success through data-driven assessment, intervention, and evaluation.

In Part 1, we covered what a Specific Learning Disability (SLD) is and which conditions fall under this category. Now comes the crucial question:

How do schools actually determine if a child has an SLD?

Both federal IDEA regulations and Texas law allow schools to use one of two research-based methods, and explicitly prohibit an older approach that you might have heard about. Let's break down what this means for your child's evaluation.

The Two Permitted Methods

When evaluating a child for SLD, the school's evaluation team must show that the child has inadequate achievement in one or more academic areas. But that's not enough on its own. The team must also use one of these two approaches:

Method 1: Response to Intervention (RTI) Model

What it is: This method looks at how your child responds to high-quality, research-based instruction and interventions over time.

The criterion: The child does not make sufficient progress to meet age or state-approved grade-level standards in the identified area(s) when provided with scientific, research-based intervention.

What this looks like in practice:

• Your child receives targeted, evidence-based interventions in the general education classroom

• Progress is carefully monitored using frequent assessments (often weekly or bi-weekly)

• Data shows that despite appropriate, intensive intervention, your child isn't making expected progress toward grade-level standards

Required documentation includes:

• A statement of the specific instructional strategies used

• Student-centered data collected during the intervention

• Documentation that parents were notified about:

  • What performance data would be collected

  • What general education services were provided

  • Strategies for increasing the child's learning rate

  • The parents' right to request a full evaluation

Key advantage: This method doesn't rely on a single test score. Instead, it shows how your child responds to quality teaching over time.

Method 2: Pattern of Strengths and Weaknesses (PSW) Model

What it is: This method involves a comprehensive assessment to identify a specific profile of abilities, areas where your child excels, alongside areas of significant difficulty.

The criterion: The child exhibits a pattern of strengths and weaknesses in performance, achievement, or both, relative to age, state-approved grade-level standards, or intellectual development.

What this looks like in practice:

• Your child undergoes comprehensive testing across multiple domains

• Evaluators look for meaningful differences between areas of ability

• For example: strong verbal reasoning but significant difficulty with phonological processing and reading

• The evaluation team determines that this pattern is relevant to identifying an SLD

Required documentation includes:

• Results from appropriate assessments showing the pattern

• An explanation of why the team finds this pattern relevant to SLD identification

• Evidence that the pattern isn't explained by other factors (more on this in Part 4)

Key advantage: This approach can identify SLD in children who may have been receiving interventions informally or who come from schools without established RTI systems.

Can Schools Choose Either Method?

Yes. Both IDEA and Texas law permit Local Educational Agencies (LEAs) to use either the RTI model or the PSW model. The school district doesn't have to use the same method for every child; the evaluation team can select the approach that best fits the individual situation.

However, once an evaluation begins, the team should be clear about which approach they're using, as it affects what data needs to be collected.

The Method That's Explicitly Prohibited

Here's what federal and Texas law make crystal clear: State criteria for SLD identification must NOT require the use of a severe discrepancy between intellectual ability and achievement.

What is the "severe discrepancy" model?

This is the old approach where schools would:

1. Give a child an IQ test

2. Give achievement tests in reading, writing, or math

3. Look for a significant gap (usually a 22-point difference in Standard Scores) between IQ and achievement scores

4. Identify SLD only if this gap existed

Why is it prohibited as a requirement?

Research showed this approach had serious problems:

• It often resulted in a "wait to fail" approach; children had to fall far enough behind before qualifying

• It didn't work well for children with higher IQs (who could struggle significantly but still score above the cutoff)

• It didn't work well for children with lower IQs (who might have an SLD but not show a large enough discrepancy)

• A single test score could keep a truly struggling child from getting help

Important note: While states cannot require this method, Texas (like federal law) doesn't prohibit considering cognitive testing as part of a comprehensive evaluation. The key is that a severe discrepancy cannot be the sole or required criterion.

In fact, Texas explicitly states: "The presence of a significant variance (severe discrepancy) among specific areas of cognitive function or between specific areas of cognitive function and academic achievement is not required when determining whether a student has a specific learning disability."

What This Means for Your Child

Collaboration and data analysis are key parts of identifying a Specific Learning Disability (SLD). Educators and specialists review progress-monitoring data, assessment results, and patterns of strengths and weaknesses to make informed decisions about student eligibility and support.

Understanding these methods empowers you to:

• Ask which method the school plans to use and why they've chosen that approach

• Request the documentation required for whichever method is being used

• Understand that one test score isn't enough, whether it's RTI data over time or a comprehensive PSW assessment, identification requires multiple data points

• Know your rights. If your child is participating in RTI, you have the right to request a full evaluation at any time

Both Methods Require More Than Just Testing

Regardless of which method is used, the evaluation team must also:

• Ensure inadequate achievement isn't due to lack of appropriate instruction (we'll cover this in Part 4)

• Rule out other factors as the primary cause of difficulties

• Document observations of your child in the learning environment

• Consider multiple data sources and assessment tools

What's Next?

Now you understand the two pathways to SLD identification. But what specific data and documentation must schools collect during this process?

In Part 3 of this series, we'll look at the evidence required for SLD identification, from classroom assessments to progress monitoring data to specialized testing requirements, especially when dyslexia is suspected in Texas.

Understanding the identification methods helps you know what to expect during the evaluation process and ask the right questions at team meetings.

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