Validity of Alternative Approaches to the Identification of LD by 1Z6o2ZC8

VIEWS: 10 PAGES: 25

									    Validity of Alternative Approaches to the
Identification of LD: Operationalizing Unexpected
                 Underachievement
      Jack M. Fletcher, Ph.D.                                                                      Carolyn Denton
      U of Texas- Houston                                                                          U of Texas- Austin

                                                      CARS.uth.tmc.edu
                                                  Jack.Fletcher@uth.tmc.edu




Responsiveness-to-Intervention Symposium
December 4-5, 2003 • Kansas City, Missouri

The National Research Center on Learning Disabilities, a collaborative project of staff at Vanderbilt University and the University of
Kansas, sponsored this two-day symposium focusing on responsiveness-to-intervention (RTI) issues.

The symposium was made possible by the support of the U.S. Department of Education Office of Special Education Programs. Renee
Bradley, Project Officer. Opinions expressed herein are those of the authors and do not necessarily represent the position of the U.S.
Department of Education.

When citing materials presented during the symposium, please use the following: “Fletcher, J. M., & Denton, C. (2003, December).
 Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
 unexpected underachievement. Paper the identification of LD: Operationalizing unexpected underachievement. Paper
Validity of alternative approaches to presented at the National Research Center on Learning Disabilities Responsiveness-to- presented at the 1
National Research Center on Learning Disabilities Responsiveness-to-Intervention Symposium, Kansas City, MO.”
 Intervention Symposium, Kansas City, MO.
   Learning Disabilities is a Construct
 • Essential aspect of construct is “unexpected
   underachievement”
 • Constructs do not exist independently of how
   they are measured; all measures are imperfect
   indicators of constructs (latent variables)
 • Measurement depends on definition
 • Definitions and the resultant identification criteria
   derive from classifications
 • All classifications are hypotheses that must be
   tested
Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           2
Intervention Symposium, Kansas City, MO.
   Learning Disabilities is a Construct
 • Does the identification model that is derived from
   the classification identify a unique subgroup of
   underachievers?
 • Children may be validly identified even when the
   underlying classification does not yield a unique
   subgroup: is the classification valid?
 • Validity of classifications only be tested on
   variables not used to form the classification-
   cognitive skills, response to intervention,
   neuroimaging, genetics
 • Validity assumes reliability

Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           3
Intervention Symposium, Kansas City, MO.
              LD is a Valid Classification
 Learning disabilities are real! Stands up across
    definitional variation (doesn’t help identify
    individuals)
   Children and adults with different forms of LD
    can be reliably and validly differentiated from
    each other, typical achievers, and other
    disabilities on cognitive correlates, response to
    intervention, neural correlates, and heritability
 What happens when we apply these criteria to
    different classifications?

Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           4
Intervention Symposium, Kansas City, MO.
        Alternative Classification Models
 1. Different forms of discrepancy: VIQ, PIQ,
   Listening comprehension- reading
   comprehension
 2. Low achievement
 3. Intra- individual differences
 4. Response to intervention
 5. Hybrid models

Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           5
Intervention Symposium, Kansas City, MO.
          Alternative Discrepancy Models:
                  Discrepant vs. LA
                (Fletcher et al., 1994)
                             Aptitude Measure                                      Outcome                                Eta2


                                          FSIQ                             Word Recognition                                .07
                                           PIQ                             Word Recognition                                .11
                                           VIQ                             Word Recognition                                .07
                                          FSIQ                                 Reading                                     .01
                                                                             Comprehension
                                   Listening                                   Reading                                     .10
                                 Comprehension                               Comprehension

80% impaired under all definitions; difference is in people above the
low achievement cut point, but below the regression cut point
  Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
  unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           6
  Intervention Symposium, Kansas City, MO.
                    130
                    120
                                                                                                                    VIQ (.62)
                    110
                                                                                                                           FSIQ (.58)
      Achievement




                    100
                                                                                                                                   PIQ (.37)
                     90
                                                                                                          Low Achievement
                     80
                     70
                     60
                     50
                           60             70             80              90            100            110             120            130
                                                                                 IQ




Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-                       7
Intervention Symposium, Kansas City, MO.
                                  Low Achievement
 • Designate a cut point on the achievement
   dimension
 • Strengths: Strong validity, linked to intervention,
   easy to implement
 • Weaknesses: Cut point, does not measure the
   underlying construct (can’t differentiate
   subgroups of poor readers when the cause is
   known to be related to emotional difficulty,
   economic disadvantage, and inadequate
   instruction)
 • Necessary but not sufficient

Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           8
Intervention Symposium, Kansas City, MO.
                  Intra- Individual Differences Model


        “while IQ tests do not measure or predict a
       student’s response to instruction, measures of
       neuropsychological functioning and information
       processing could be included in evaluation
       protocols in ways that document the areas of
       strength and vulnerability needed to make
       informed decisions about eligibility for services,
       or more importantly, what services are needed.”

Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           9
Intervention Symposium, Kansas City, MO.
                  Intra- Individual Differences Model



        “An essential characteristic of SLD is
       failure to achieve at a level of expected
       performance based upon the student’s
       other abilities (NCLD, 2002, p. 4).”

 Another version of a 2 test (or more)
  discrepancy?
Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           10
Intervention Symposium, Kansas City, MO.
       Biobehavioral Systems Model
                                                             Manifest
                                                             Disability


                                                              Child Traits

                                      Cognitive                                Psychosocial




                                   Biological                                   Environmental
                                    Factors                                        Factors




Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           11
Intervention Symposium, Kansas City, MO.
                                                    Problems
 • Processing subtypes, patterns weakly related to
   intervention outcomes (if at all)
 • Not sure of what processes to measure outside word
   recognition
 • What about non- MR children with flatter profiles?
   (Biased towards milder impairments because severity is
   correlated with shape)
 • Perpetuates assessment model (test and treat) that has
   not been effective in enhancing outcomes
 • Difficult to scale (send all school psychologists to NP
   school?)
 • But: strong validity at achievement level (What
   information is added outside variation in achievement
   domains?)
Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           12
Intervention Symposium, Kansas City, MO.
                 Response to Intervention
 • Serial curriculum- based assessments of learning in
   relation to an intervention
 • Identification is more reliable than when based on a
   single assessment, even if the intercept is used
 • As one criterion, student may be LD if they do not
   respond to instruction that works with most other
   students (I.e., unexpected underachievement)
 • Identifies a unique subgroup of underachievers that
   reflects an underlying classification that can be validated
   (Al- Otaiba & Fuchs, 2002; Vellutino et al., 2003;)



Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           13
Intervention Symposium, Kansas City, MO.
             What percentage of G1 children don’t respond
                  adequately to quality intervention?
                         (Mathes et al., 2003)


        Primary only: 14/90 = 16% (3% of school
        population)
        Primary + Secondary:
         Proactive: 1/82 = < 1% (< .2% of school
          population)
         Responsive: 7/83 = 8% (<1.5% of school
          population)

        (Woodcock Basic Reading < 30th percentile)
Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           14
Intervention Symposium, Kansas City, MO.
 Severe RD before and after 8 week
 intervention (7- 17 years old) Simos
             et al. (2002)




Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           15
Intervention Symposium, Kansas City, MO.
                                                Not At Risk




Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           16
Intervention Symposium, Kansas City, MO.
                            At Risk: Responders




Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           17
Intervention Symposium, Kansas City, MO.
                    At Risk: Nonresponders




Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           18
Intervention Symposium, Kansas City, MO.
                                         What about the Nonresponders
                                               (Grade 2 and 3)?

             Wave 1                               Wave 2                                 Wave 3                                 Wave 4

Round 1                   Phono-Graphix                         Read Naturally
                  Pre                                   P                                     RN
                              8 weeks                               8 weeks                                8 weeks


Round 2           Pre         Baseline                  Pre      Phono-Graphix P                         Read Naturally RN

                              8 weeks                               8 weeks                                 8 weeks




 Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
 unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-                19
 Intervention Symposium, Kansas City, MO.
Woodcock-Johnson III Basic Skills Standard Scores
                          90




                          88



                          86




                          84



                          82



                          80



                         78
                         Baseline                       Pretest                 Phono-Graphix                 Read Naturally

Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           20
Intervention Symposium, Kansas City, MO.
  Gray Oral Reading Test Fluency Standard Scores
                         5.5




                         5.0




                         4.5




                         4.0




                         3.5




                         3.0
                         Baseline                      Pretest                 Phono-Graphix                Read Naturally

Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           21
Intervention Symposium, Kansas City, MO.
                Gray Oral Reading Test Comprehension
                          8.0




                          7.5



                          7.0




                          6.5



                          6.0



                          5.5



                          5.0
                          Baseline                      Pretest                 Phono-Graphix                 Read Naturally

Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           22
Intervention Symposium, Kansas City, MO.
                          16


                          14


                          12


                          10


                            8


                            6
                                                                                                                         1st visit

                            4                                                                                            2nd visit

                            2                                                                                            3rd visit
                                          R>L or L=0                                     L>R

                                           STGp Activity (Pseudowords)
Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-             23
Intervention Symposium, Kansas City, MO.
                                                    Problems
 • What is the best cut point? (index to
   benchmarks, growth, norm referenced scores:
   probably makes little difference if measurement
   error taken into account; don’t make it a formula)
 • Scaling and implementation: problem is not with
   the research base, but with its scaling (so what
   else is new? 30 years later we still can’t do IQ
   discrepancy correctly)
 • Necessary but not sufficient: needs additional
   criteria

Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           24
Intervention Symposium, Kansas City, MO.
       OSEP LD Summit: Hybrid Model
 • 1. Low Achievement
 • 2. Apply the Exclusions
 • 3. Evaluate Response to Intervention
 (maintain flexibility of the interdisciplinary
   team)

 Unlike other alternative models, may yield a
  valid classification of unexpected
  underachievers
Fletcher, J. M., & Denton, C. (2003, December). Validity of alternative approaches to the identification of LD: Operationalizing
unexpected underachievement. Paper presented at the National Research Center on Learning Disabilities Responsiveness-to-           25
Intervention Symposium, Kansas City, MO.

								
To top