Since 2004 with the re-enactment of the Individuals with Disabilities in Education Act, the movement in education has been a Response to Intervention (RTI) approach in order to qualify a student as learning disabled. Previously, graduate programs around the country taught clinicians how to diagnose students as learning disabled using an IQ-Achievement discrepancy model. What are these two models of identifying students as having learning disabilities, including dyslexia, and what are the pros and cons of each?
IQ- Achievement Discrepancy Model
Under this model, educational teams usually led by a school psychologist show a discrepancy between overall intelligence and skill achievement. Typically, this discrepancy needs to be greater than 2.0 standard deviations, or 30 points. For example, a child with an overall intelligence score of 100 as measured by a standardized test such as the Wechsler Intelligence Scale for Children, but a skill performance score of 70 would qualify as being learning disabled.
The problem with this qualification model is that it basically requires a child to be failing in order to receive extra help at school. As a result, these services typically do not start until third grade or later, as there is not a big enough discrepancy between overall IQ and achievement until this point for most students.
In the opinion of this author, one benefit of this approach is that the psychologist or LD teacher often use a number of processing tests such as can be found on the Woodcock Johnson Test of Cognitive Abilities in order to look at individual processing strengths and weaknesses.
While all children need systematic research-based instruction, teachers can accommodate learning styles for individual children based on the results of processing tests. For example, “Joe, you have really strong abilities to see information and do something with it. However, when you just hear things, it’s harder for you to remember. I bet it's hard for you when your teacher is standing up in front just talking, but you are really good at puzzles." An accurate processing report makes a child's face light up, as someone finally "gets it."
Using information from processing tests, educators can help children learn study skills playing on their strengths. They can also accommodate a child's weaknesses by adapting learning inputs and methods of assessment.
A few real world examples:
1. A child presents with stagnant scores on curriculum based reading measures of oral reading fluency. The child is assessed for special education services and it's determined that the child has moderate word retrieval difficulty by the speech-language pathologist. Word retrieval can affect the speed of oral reading fluency. Therefore the team decides to provide a testing accommodation, using silent reading with multiple choice answers in lieu of oral reading fluency to assess progress.
2. Another child has difficulties with visual processing. In order to accommodate these needs, the teacher limits the number of math questions on each page for the child. Within writing, the teacher can accommodate the visual processing weaknesses by providing simple graphic organizers without extra words and cute decorations as these can be distracting for the child. The child can also be instructed to use a notecard while reading in order to eliminate excessive visual input, and the teacher will spend extra time helping the child learn strategies how to read content books like social studies and science where text is placed all over the page in different blocks and bubbles.
3. A child receives a diagnosis of Central Auditory Processing Disorder from an audiologist. With this type of processing difficulty, a child may have difficulty discriminating the teacher's voice from classroom background noise. Accommodations may include pairing the student with a direction buddy who can repeat directions as needed and sitting the student next to the teacher during lecture-style instruction. The teacher will also be encouraged not to play music during partner-work times, as this will may make it harder for the student to work quietly with a friend.
Can we try out all these accommodations without processing tests? Yes. However, it is not as time efficient. It also often results in a menu-style listing of accomodations for every child, which is not as effective.
Response to Intervention (RTI) Model
Under best practice RTI, all children are universally benchmarked several times a year in various academic skill areas (reading, math, language). The data from the benchmarks helps determine which children are below average compared to their peers and measures the rate of growth across the year. Using this data, teachers create "tiers" of instruction. Tier 1(green at the top) includes general education curriculum. For students who score low, teachers/aides can provide extra small group instructional support in addition to the general education "tier 1" curriculum. This extra help is called Tier 2. Educators should continually monitor the progress of children in these small "tier 2" groups. If the children make progress, they remain at Tier 2. If not, the educators initiate a "tier 3" discussion that includes the full educational team: administration, school psychologist, other special education support staff, teacher, and parents.
At the tier 3 discussion, the team discusses how to create an individualized plan to help the student. Sometimes, a school will provide Tier 3 support without a special education qualification if the team feels that the child's skills will improve in a timely manner and allow for movement out individualized support within the year (note: Tier 3 can be provided in "groups;" However, unlike Tier 2 with a group goal, at Tier 3 the learning goal must be tailored to the individual child.) As part of the team discussion, most schools open a full case study evaluation in order to consider qualifying a student as learning disabled. During this case study, data taken from the student's academic performance within each past "tier" of instruction can be used to qualify a student as learning disabled. No IQ test and no processing tests are required.
The benefit of the RTI model is that teachers do not wait until a child fails to give extra help, like they often do under the discrepancy model. RTI is a much more proactive, preventative model. Many schools begin RTI services as early as pre-school and kindergarten. Another pro of the RTI model is that it puts less emphasis on IQ testing. Intelligence is a malleable trait, and if our goal is to teach children, assigning a cap to their intellect is unnecessary.
In the opinion of the author, one of the problems with the RTI model is that many special education teams no longer specifically assess processing abilities since it is not required for learning disabilities qualification under the Individuals with Disabilities Act of 2004. An inventory of strengths and weaknesses is still required within the Individualized Education Plan (IEP). However, teams often trial different teaching methods to see if the child "responds to the intervention", as the RTI name states. This trial and error method can miss weaknesses. It also takes time to pinpoint a child's true strengths. By contrast, a general cognitive profile hypothesis confirmed by targeted processing tests can pinpoint strengths and weaknesses immediately so that teaching methods can be modified and appropriate learning accommodations can be provided.
What's Best Practice?
In the opinion of the author, best practice is a merging of these two approaches. School teams can use early intervention principles inherent in the RTI approach. However, if a student does not progress with general education instruction in combination with extra Tier 2 support, then the educational team opens a full case study that includes processing tests. Using this information, the Tier 3 plan includes specific accommodations based on the student's learning profile. The educational specialist providing the Tier 3 support can also use the student's processing test performance in order to tailor an individualized instruction plan. Finally, the team can teach the student about his/her learning profile. Helping a student build metacognitive awareness about his or her own learning style is one of the most empowering things an educator can do.