Identifying Specific Learning Disabilities: Understanding RTI, PSW, and the Discrepancy Model
How Oregon schools identify Specific Learning Disabilities—and what parents should understand about the evaluation process.
When a child struggles with reading, writing, or math, parents often expect testing to provide a straightforward answer: Does my child have a learning disability or not?
In reality, identifying a Specific Learning Disability (SLD) involves more than looking at a single test score. Evaluation teams consider multiple sources of information and must determine not only whether a student demonstrates characteristics of an SLD, but whether the disability adversely affects educational performance and whether the student needs special education as a result.
Parents may also encounter terms such as Response to Intervention (RTI), Patterns of Strengths and Weaknesses (PSW), and the ability-achievement discrepancy model. These approaches are related to SLD identification, but they are not interchangeable—and understanding the differences can make an evaluation report much easier to interpret.
How Specific Learning Disabilities Are Identified in Oregon
Oregon's current special education rules describe two approaches that may be used as part of a comprehensive evaluation for SLD:
a Response to Intervention (RTI) model; or
a model based on a student's patterns of strengths and weaknesses (PSW).
Regardless of the approach, Oregon requires considerably more than a score or formula. The evaluation includes academic assessment, review of educational records and work samples, observation, progress-monitoring information, and other assessment when needed.
The team must also consider whether the student's difficulties are primarily the result of other factors, including certain disabilities, cultural factors, environmental or economic disadvantage, or limited English proficiency. Ultimately, eligibility requires both an adverse impact on educational performance and a need for special education services as a result of the disability.
That means SLD identification should be understood as a comprehensive evaluation process, not simply a particular test or cutoff score.
1. Response to Intervention (RTI)
RTI examines how a student responds to increasingly targeted, evidence-based instruction and intervention.
You may be familiar with a tiered framework such as:
Tier 1: Core instruction provided to all students
Tier 2: Additional targeted intervention for students needing support
Tier 3: More intensive and individualized intervention
When RTI is used as part of an SLD evaluation in Oregon, the evaluation must include information about the type, intensity, and duration of interventions provided; the student's rate of progress; how that progress compares with expected progress; and appropriately scheduled progress monitoring.
ODE currently supports Oregon districts implementing RTI systems through the Oregon Response to Instruction & Intervention initiative, including using RTI as a framework for SLD identification.
What parents should understand about RTI
Intervention data can provide valuable information that standardized testing alone cannot: How does this student actually respond when provided targeted instruction?
But RTI is not supposed to become a reason to indefinitely postpone an evaluation.
The U.S. Department of Education has specifically warned that an RTI process cannot be used to delay or deny a timely evaluation when a child is suspected of having a disability.
Questions parents can ask
What specific intervention did my child receive?
How often, for how long, and in what size group?
How was progress measured?
What does the progress-monitoring data show?
How does my child's rate of progress compare with expected progress?
Was the intervention implemented consistently?
What other evaluation information was considered alongside the intervention data?
2. Patterns of Strengths and Weaknesses (PSW)
A Patterns of Strengths and Weaknesses approach examines whether the student demonstrates a meaningful pattern of strengths and weaknesses relevant to identifying an SLD.
Oregon's rule describes this as a pattern in classroom performance, academic achievement, or both, relative to age, Oregon grade-level standards, or intellectual development.
This distinction matters because PSW is sometimes described too simply as:
high IQ + low academic score = learning disability.
That's not what Oregon's current rule says.
Cognitive assessment may be appropriate when a student exhibits concerns in that area, but Oregon's required SLD evaluation is broader and does not automatically require an IQ test for every student suspected of having an SLD.
A well-conducted evaluation integrates the student's academic performance, classroom functioning, educational history, progress-monitoring data, observations, assessment results, and other relevant information to determine whether the overall pattern is consistent with an SLD.
Questions parents can ask
What strengths and weaknesses did the team identify?
What evidence supports that pattern?
How does the pattern relate to my child's actual academic difficulty?
What information came from classroom performance versus standardized testing?
What other explanations for the difficulty were considered?
How did the team move from the individual pieces of data to its overall conclusion?
3. What About the Discrepancy Model?
Parents may still encounter the term “discrepancy model,” particularly when researching learning disabilities online or discussing older evaluations.
Traditionally, an ability-achievement discrepancy approach looked for a significant difference between a student's measured intellectual ability and academic achievement.
This approach became associated with the criticism that students sometimes had to struggle significantly before demonstrating a large enough discrepancy to meet eligibility criteria—hence the phrase “wait to fail.”
IDEA changed the federal framework for SLD identification. Federal regulations now state that a state cannot require the use of a severe discrepancy between intellectual ability and achievement and must permit an RTI-based process.
Oregon's current SLD rule describes RTI and strengths-and-weaknesses approaches rather than establishing severe ability-achievement discrepancy as a separate SLD identification model.
So if you're reading an Oregon evaluation today, you are more likely to encounter RTI or PSW language than a traditional severe-discrepancy formula.
Why Two Evaluations Can Reach Different Conclusions
This is often the question parents are really asking.
Two evaluations can contain similar scores and still differ in how those data are interpreted.
That doesn't necessarily mean one evaluator is right and the other is wrong.
Evaluators may differ in the questions being investigated, assessments selected, information available, interpretation of the student's educational history, or conclusions drawn from the overall pattern of data.
This is why individual test scores should not be interpreted in isolation.
When reviewing an evaluation, some of the most useful questions are:
Does the report clearly explain why the student is struggling?
Are conclusions supported by multiple sources of data?
Does the interpretation fit what is actually happening in the classroom?
Were relevant areas of concern adequately evaluated?
Does the report explain why alternative explanations were accepted or ruled out?
Can you follow the reasoning from the data to the team's conclusion?
A strong evaluation should help you understand the student—not simply tell you whether a cutoff was met.
What If My Child Is Struggling but Doesn't Qualify?
Not qualifying for special education does not necessarily mean that a child's difficulties aren't real.
IDEA eligibility requires more than the presence of a learning difference. In Oregon, the team must determine that the student meets the criteria for a disability, that the disability adversely affects educational performance, and that the student needs special education services as a result.
A student who does not meet those requirements may still need intervention, accommodations, general education supports, or further evaluation depending on the circumstances.
If the evaluation leaves you with unanswered questions, it can be helpful to identify what you still don't understand before assuming that more testing is necessarily the answer.
When Additional Review May Be Helpful
You may want a closer review of an existing evaluation when:
the results don't seem to explain the difficulties you're seeing;
significant areas of concern appear not to have been evaluated;
you're unclear how the team reached its conclusions;
different sources of data seem contradictory;
your child continues to struggle despite intervention; or
you simply received a large evaluation report and aren't sure what all of the information means.
Sometimes additional assessment is appropriate. Sometimes the existing data already contain the answer but need to be interpreted more clearly. And sometimes the next step is better intervention or support rather than more testing.
The important question is not simply “Which model did they use?”
It's: “Does this evaluation give us enough reliable information to understand this student and make appropriate educational decisions?”
Need Help Understanding an Evaluation?
Educational Services Collective offers Record Review + Consultation for Oregon families who want help understanding existing evaluation data, identifying unanswered questions, and considering possible next steps.
For families considering an independent evaluation, reviewing the existing information first can also help determine whether additional testing is warranted and, if so, what questions an evaluation should address.
