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The Individuals with Disabilities Education Improvement Act (IDEA, 2004) specifies eight areas that constitute a learning disability: oral expression, listening comprehension, basic reading skills, reading fluency skills, reading comprehension, mathematics calculation, mathematics problem solving, and written expression. However, IDEA does not specifically state the assessment procedures needed to procure a learning disability classification and allows state governments the freedom to choose their own criteria. The majority of clinicians choose between three potential assessment procedures in the assessment of learning disabilities: the IQ-achievement discrepancy method, responsiveness to intervention, and comprehensive assessment (Weiss, 2014)
IQ-Achievement Discrepancy Method
The IQ-achievement discrepancy method was originally considered the gold standard for identifying learning disabilities in the classification of school-age children. The procedure was supported by the DSM-IV’s definition as a significant discrepancy between an IQ score (cognitive ability) and academic achievement as assessed via standardized tests. Students who scored significantly lower on an individually administered standardized achievement test as compared with their results from an individually administered standardized IQ test indicated unexpected underachievement that constituted a learning disability. Interestingly, no description of what constitutes a significant discrepancy was given by IDEA so state officials tended to adopt a discrepancy of 1 – 2 standard deviations or approximately 15-30 points between the achievement and IQ scores (Weiss, 2014).
There appears to be an overwhelming consensus today that employing the IQ-achievement discrepancy alone is an inadequate approach due to four weaknesses (Weiss, 2014):
1) Many school-age children who manifest significant delays in reading do
not meet the state decided criteria as a cutoff and therefore do not receive
services until they fall even further behind. This approach has been aptly
termed as the “wait to fail approach.”
2) Brain imaging studies have not shown any distinction in the brains of
children who show significant IQ-achievement discrepancies and those
without. In other words there are no biological markings that show a
distinction between those with discrepancies in the IQ-achievement
criterion and those who are just low-achieving children.
3) There are no distinct differences between low-achieving children who do
not meet the IQ-achievement discrepancy criterion and the latter who do
when it pertains to the processing of information. Both groups display
similar difficulties with recognizing letters and words, vocabulary
knowledge, short-term memory and even classroom behavior problems.
4) Both groups seems to respond to treatment equally which means that
there is no need to teach using different methods to the hypothesized
Response to Intervention (RtI)
An alternative method in identifying children with learning disabilities that is often employed by psychologists and others is called response to intervention (RTI). Those children who continue to have difficulties in making academic progress after educators have employed empirically validated instruction interventions may be classified with a learning disability. RTI usually relies on a three-tier system as part of the identification process (Weiss, 2014).
1) Tier I is conceived as a primary preventive screening that constitutes
assessing all students in all classes with regard to basic academic skills
that are conducted though brief and on-going assessments throughout the
school. For example, many schools use the Dynamic Indicators of Basic
Early Literacy Skills (DIBELS) to identify those students who have
difficulties in word reasoning. The 15% of students who do not make
adequate progress are deemed nonresponsive to the empirically validated
educational intervention and progress to Tier II.
2) Tier II is deemed a secondary prevention because it is employed on
children who demonstrate academic delays but are not classified with a
learning disability. Tier II often uses small-group instruction in addition
to the regular instruction in the classroom in the particular academic area
of delay. It is often recommended that Tier II last approximately 10-20
weeks. At the completion of Tier II interventions, these students are
reevaluated to decide if they made adequate progress in which they
then can return to Tier I. The students will remain in Tier II if some
improvement has been noticed, but not enough to terminate the
intervention, or the students will progress to the next level of
intervention called Tier III.
3) Approximately 5-10% of school age children continue to show academic
difficulties even with small group instruction, which is why they are
referred to Tier III. Tier III often consists of one-on-one individualized
instruction that is specifically designed to target the academic deficits.
Some specialists argue that Tier III constitutes special education services
while other experts argue that only if children fail to progress in Tier III
should they be referred for special education services.
As with the IQ-achievement discrepancy method, there are some issues with the RTI method as well.
1) Federal law does not provide any specific guidelines on how RTI should
be used and implemented in classifying children with learning
disabilities. This means that within a state and even sometimes within a
district a child may be classified with a learning disability but a similar
child in another state would not.
2) There is ample evidence that regular general education teachers may not
be adequately trained and be proficient in implementing scientifically
based academic interventions unless they have advanced training as in the
case of reading specialists, for example (Weiss, 2014).
Comprehensive assessment is a third approach that has been adopted by clinicians to address the shortcomings of the IQ-achievement and RTI methods. This method consists of combining both of the latter approaches together to integrate norm-referenced assessment (intellectual ability, cognitive processing, and academic achievement) with assessment based on classroom observations (Weiss, 2014). There are multiple reasons why children may fail to respond positively to empirically validated interventions that are alternative explanations to having a learning disability: attention issues, low motivation, low intellectual functioning, linguistic or cultural differences, etc. In other words, not all children with academic delays have a learning disability and a comprehensive assessment approach may be useful in differentiating those with a learning disability from those students who have academic delays due to alternative explanations.
Comprehensive Model for Learning Disability Identification
Flanagan and colleagues developed a model that incorporates norm-referenced cognitive and academic assessment with RTI. Just as in RTI, this model incorporates several tiers that progresses with more individualized services. However, this model requires clinicians to assess the cognitive abilities and processing skills of those children who fail to benefit from the individualized instruction to help determine whether or not a learning disability is present as a diagnosis that can also be important in treatment planning by designing specific interventions towards the strengths and weaknesses of the children (Weis, 2014).
Implications for the classroom
It is incumbent upon teachers and other professionals to recognize students with learning difficulties but it is also important to differentiate those students who have a learning disability from those who have alternative reasons for their academic delays. The comprehensive model for learning disability identification is a step in the right direction that addresses much of the shortcomings of the IQ-achievement discrepancy and RTI models.
Weiss, R. (2014). Abnormal Child and Adolescent Psychology. Washington, D.
C.: Sage Publications.
Michael David Benhar, Ph.D. is an Associate Professor in the Social Sciences Department at Suffolk County Community College. Dr. Michael David Benhar teaches undergraduate and graduate courses in Developmental Psychology, Exceptional Child, Classroom Management, and Assessment. He has co-authored a chapter on students with disabilities. In addition, he has worked as a school psychologist in a preschool for children with special needs. Contact Dr. Michael Benhar at email@example.com.