Issues and Solutions Regarding
Dual Discrepancy
Rationale for the shift to the DD model:
There were a number of problems with using IQ as the predictor
variable, summarized below;
– For students with IQ scores between 84 and 71 (“below average”), it was quite
difficult to be identified as SLD using a 16 to 20 severe point discrepancy criteria
– Likewise, students with IQ scores between 116 and 129 (“above average”)
required much more than a 16 to 20 point discrepancy in order to show a need
for services (in other words, to have an academic achievement score of 84 or
below)
– When using the Severe Discrepancy model, a student was often tested in
academics during a single session (or two/several within a short period of time).
The DD model requires at least two academic achievement data points for Factor
2. Thus, performance over time is considered in the DD model, unlike with the
SD approach.
– When using the District Average score on a grade level standards and
benchmarks measure as the predictor variable, it can be argued that one is using
a predictor that is directly more relevant to academic achievement than is IQ
DD and the Shifting Role of the
SAT Team
Previously the SAT team was the gatekeeper for special
education referrals with an implicit goal of getting the
child the needed services as quickly as possible.
Currently the SAT team will be the de facto IEP team for
85% to 95% of students, including those Tier 2 children
who formerly were referred for testing
The role of the SAT team has shifted from referral
management to case management. Likewise, the role
has shifted from making referrals as quickly as possible
to helping children stay in the “least restrictive
environment”
DD and the Changing
Role of the Diagnostician
Shifting Diagnostician Role
–
By calculating the DD data during the
SAT process, the SAT members can
know what the likely outcome of the
Tier 3 evaluation result will be prior to
making a referral for testing.
–
But is it unimportant to know the child’s
IQ test, even if that factor is not the
best predictor variable? NO!!!
–
A referral may be still be made, even in
the case where a child doesn’t meet
Factor 1 in the DD analysis in order to
determine why Tier 2 interventions
have not proven effective
–
The role of the Diagnostician is shifting
from determination of eligibility to
expert in cognitive processing in the
learning process
–
The most important part of the
diagnostic report will now become: a)
the cognitive processing analysis and
b) suggested interventions to deal with
processing deficits and individualized
learning style
–
Diagnosticians will need to learn more
about the theory and practice of
reading/math/writing instruction
–
Diagnosticians will likely need to shift
somewhat to a preventative model via
increased consultation with SAT team
Cognitive Information Processing and the Learning Process
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Auditory Sound Perception
Sound/Word Discrimination
Oral Expression/Vocabulary
Receptive Language
Sound-Symbol Association
Knowledge
Phonological/Phonemic
Awareness
Short Term Auditory Memory
Long Term Auditory Memory
Auditory Complex Reasoning
Integration of Verbal-Visual
Processing
Auditory Fluency
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Attention Span/Concentration
Organization
Anticipation/Planning
Self-Monitoring
Self-Direction
Impulse Control
Cognitive Fluency
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Visual Perception
Visual-Motor Integration
Visual Discrimination
Visual Orientation and Sequencing
Visual Tracking
Visual Short Term Memory
Visual Categorizing of Concepts
Visual-Spatial Abstract Reasoning
Integration of Visual-Verbal Processing
Visual-Spatial Fluency
Challenges With Using the Dual
Discrepancy Model
Challenge One: Late Fall or Early Spring Referrals
•
At present the PED short cycle data bank has included fall and spring
scores, but not winter. This has several significant implications for the SAT
team (and diagnosticians).
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Since the only DD comparison that can be made is between August and
April short cycle scores, it is thus most expedient to work referrals that come
to conclusion shortly before the final short cycle testing in April. This will
have the impact of pressing the diagnosticians for completion before the
end of the school year.
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Referrals made during fall or early spring semester will thus not be able to
include the Factor 2 part of Dual Discrepancy using state norms (and since
the diagnosticians have the 60 day timeline, testing must proceed as soon
as the referral comes to conclusion).
Challenges With Using the Dual
Discrepancy Model
Challenge Two: What To Do When Factor 2 DD Analysis Is Not Available
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At present, the PED state-wide norms do not appear to include slope or difference data. Thus, the Factor 2
analysis is a challenge to accomplish.
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It is recommended that local district-wide data be used for a Factor 2 comparison between fall and winter
be conducted in lieu of state normative data. That is, local data is preferable to no data at all when
addressing the 2nd factor in the DD equation.
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In order to do this, someone in the district will be responsible for a fairly significant grade level data input analysis.
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Data will be need to be entered in a spreadsheet for every student in the district for the grade under consideration.
The data to be entered is the fall and winter short cycle scores for the area(s) of referral. (NOTE: It could also be
appropriate to compare winter and spring scores.)
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Additionally, the difference between the winter and fall score will need to be calculated for each student in the
grade within the district.
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The mean and standard deviation of the difference scores for the grade level must be calculated at the district
level – then the “local norms” DD assessment for Factor 2 can occur for the individual student.
Challenges With Using the Dual
Discrepancy Model
Challenge Three: Deciding What Additional Information (To Establish A Pattern Of Strengths and
Weaknesses) Is Necessary When Factor 2
Is Not Significant or Not Available
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A Severe Discrepancy analysis should be conducted in the areas of concern.
However, even if that analysis is positive for an SD in the area(s) of concern,
additional information is needed. That is, a single SD on a single academic
achievement test is not sufficient to replace the lack of Factor 2 in the Dual
Discrepancy analysis.
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If possible and when appropriate, use a second academic achievement test in the
Dual Discrepancy analysis.
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Include NMSBA results from previous school year in the area(s) of identified concern.
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Include Curriculum Based Measures (CBM) in the area(s) of identified concern
Challenges With Using the Dual
Discrepancy Model
Challenge Four: Deciding What Information
Can Be Analyzed When No Short Cycle Results Are Available
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PED guidelines require each district to have a measurement of key
academic skills in each grade level (from K through 12). However, a review
of the PED aggregate test results from 2009-2010 shows fewer measures
available in kindergarten and 1st grades than 2nd or 3rd.
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The SLD categories of Oral Expression and Listening Comprehension are
not often reflected in the short cycle testing options at many school districts.
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In distinguishing reading from written expression while using a DD analysis,
use diagnostic academic achievement test evaluation testing results in
order to make an argument for a distinction between reading and language
arts if the short cycle results combine these factors.