Learning Disabilities

Gary L. Cates ,Ph.D. N.C.S.P

Illinois State University

What is a learning disability?

• Take a moment and write down your answer.

Kirk (1963)

• "Children with special learning disabilities exhibit a disorder in one or more of the basic psychological processes involved in understanding or in using spoken or written language. These may be manifested in disorders of listening, thinking, talking, reading, writing, spelling, or arithmetic. They include conditions which have been referred to as perceptual handicaps, brain injury, minimal brain dysfunction, dyslexia, developmental aphasia, etc. they do not include learning problems which are due primarily to visual, hearing, or motor handicaps, to mental retardation, emotional disturbance or to environmental deprivation."

National Joint Committee on Learning Disabilities (1989)

• Learning disabilities is a generic term that refers to a heterogenous group of disorders manifested by significant difficulties in the acquisition and use of listening, speaking, reading, writing, reasoning, or mathematical abilities. These disorders are intrinsic to the individual, presumed to be due to central nervous system dysfunction, and may occur across the life span. Problems in self-regulatory behaviors, social perception, and social interaction may exist with learning disabilities but do not by themselves constitute a learning disability. Although a learning disability may occur concomitantly with other handicapping conditions (for example, sensory impairment, mental retardation, serious emotional disturbance) or with extrinsic factors (such as cultural differences, insufficient or inappropriate instruction), they are not the result of those conditions or influences

Learning Disability

• Disorder in one or more of the 5 psychological processes (i.e. central nervous system dysfunction) that:

• Interferes with learning daily living

• Is life long

• Not a result of lack of educational opportunity

Associated Features

• 2-10% (Schools shoot about 5.5%)

• Mostly Male (80% of reading problems)

• 10-25% have behavior disorder

• Related to but not predicted by medical issues

Terms?

• Reading Disability• Specific Learning Disability• Reading Disorder• Reading Skill Deficit• Dyslexia• Dyscalcula• Dysgraphia• LD coined by Kirk (1963)

Learning Disability Diagnosis

• Discrepancy between IQ and Achievement– 15, 20, 25, 30 pts?

• Processing problem demonstrated or not?

Criteria - Illinois

• Not Achieving Adequately: Age or state level standards AND

• Not improving sufficient progress AND

• Educational Needs significantly different

• Exclusionary Criteria– Hearing, vision, cognitive, emotional, cultural,

disadvantage, Limited English

Empirical Diagnosis

Gary L. Cates, Ph.D., N.C.S.P.

Let’s Calculate Discrepancy

• IQ - Achievement100 – 85 = 15

• This assumes 1 to 1 relationship r = 1.0 100% variance explained of achievement explained by IQ

What about the correlation between the tests?

• The weaker the correlation (i.e. predictive validity of IQ) for a specific achievement test the more likely you are to identify a child without a “true” discrepancy.

• So what we need to know is the correlation between the two instruments

• Problem? Most instruments don’t provide this information because it is not collected!

Here is the Formula for regressing a score

Regressed score = (Correlation*Z )

Remember:

Z = (Score – Mean)/ SD

We can estimate Correlations between the two tests if is not

known using the following formula

.7071 is a constantrxx is the inter-item correlation of test 1ryy is the inter-item correlation of test 2

Plug all those numbers into this formula

Let’s do one together

What you know

• Student Scores 85 on WIAT and 100 on

K-ABC.• Inter-item correlation

on reading comprehension on the WIAT is .88

• Inter-item correlation on K-ABC ~ .91

What do you come up with?

• Does the child have a discrepancy?

• This still does not include the standard error of measurement being factored in.

Let’s calculate discrepancy another way

• Student scores 75 wcpm on CBM reading probe

• Peers score 115 wcpm on same CBM reading probe

• The formula is Peer performance

_________________________

Target student performance

Is it a significant discrepancy?

• Rule of thumb 2x, 1.5x

• Ensures that within a district a child in the same curriculum as the normative sample gets services if they are significantly below this normative sample

• If the student’s performance is discrepant then services are provided and the rate of performance gap monitored.

Another level of Discrepancy

• Adequate Progress (monitoring the gap)– E.g. student is making .9 words per minute

gains per week and the normative group mean for words per minute gain is 1.5 this is inadequate performance.

– E.g. student is making 1.9 words per minute gains per week and the normative group mean for words per minute gain is 1.5 this is adequate performance.

Another Analysis

• Nearly 75% of patients with left TLE, whereas fewer than 10% of those with right TLE, had at least one learning disability (reading comprehension/Written Expression).

• Brainstem Timing: Implications for Cortical Processing and Literacy (Benai, 2005)

• Smaller cortical volume (Cassanova, 2004)– What do you make of this?

Treatments for Learning Disorder/Disability

Aptitude By Treatment Interactions

• Learning Styles

• Differential Diagnosis-Prescriptive teaching (DD-PT)– Anter & Jenkins (1979)– Cronbach & Snow (1977): Meta analysis– Ayers & Cooley (1986): K-ABC– Good et al. (1993): K-ABC revisted