Changes in learning disability definitions since the 1960s – are they signaling knowledge development in this field?

  

This paper by Ruth Colker, a Law professor at Ohio State University:

Colker, Ruth.  The learning disability mess.  Journal of Gender, Social Policy and the Law (2011) vol.20, 81-106.  http://www.wcl.american.edu/journal/genderlaw/documents/02_20.1.Colker.pdf

reviews the development of learning disability definition since the 1960s.  The paper will interest those who are deeply interested in definitions.  Learning disability definition is very important because it influences differential definition (what is the main problem the child has – learning disability? Emotional disability? Learning deficits? Improper instruction?).  It influences  treatment recommendations (the type of disability will dictate the intervention chosen).  It influences policy (which children will receive extra help, who will have test accommodations, who can be licensed to diagnose learning disability?).

Six essential features can be derived of the different definitions (these features are defined by me and not by Ruth Colker).  What's interesting is  that most of these elements have been and still are under dispute!   Different definition features have been added or deleted time and again through the years – in accordance with the advance in research, with budget  constrains  that affected legislation, and with the discipline or the research group which had the upper hand at the time.

Here  are the definition features and the disputes tied with them:

The observed symptom: low achievement (in reading/writing/math/speaking/listening):

o   Should the required low achievement be compared with the population norm for the child's grade and age?  Or should it be compared with the child's achievements in other domains (meaning that a child can be defined as learning disabled although he has normal/sound achievement for his grade and age level)?  This is in dispute!

o   The different definitions define different criteria for low achievement. 

The cause is biological/neurological

o   Is there a need to prove that the low achievement results from intra-individual disorders in the central nervous system/disorders in psychological processes/significantly low specific cognitive abilities? This is in dispute!

Age of onset

• Could learning disabilities become manifested at any time throughout life?
• Or should the definition require that the symptoms be manifested during the school years?

Specificity

• Is learning disability a specific phenomenon that affects a limited area of the child's functioning and not his overall functioning?
• Or is it a broad phenomenon with wide ramifications?  This is in dispute!

General intellectual ability

• Above intellectual disability IQ level, should it be required that the child will have a discrepancy between his achievement level in reading/writing/math and his IQ score?  This is in dispute!  Although the balance leans in recent years towards abandoning   this criterion.
• If so – what will be considered a significant discrepancy?
• When a discrepancy is required, usually the definition also contains the specificity criterion, because a discrepancy means that most of the child's areas of functioning are OK.  This means that the phenomenon is specific and not a broad, general problem.

Excluding factors:

• Which are the excluding factors? In recent years there seems to be a consensus about the following excluding factors: sensory disability, intellectual disability, emotional or social disorders, cultural differences, immigration and insufficient or improper instruction.
• How should we prove that the symptoms are not resulting from excluding factors?

This situation, in which so many essential features of learning disability are in dispute, testifies perhaps to the complex nature of this phenomenon, which includes cultural and social aspects as well as cognitive and didactic aspects.

If we had easy and simple ways to tie low achievement in specific domains with specific neurological-cognitive markers, maybe it would have been easier to reach a consensus definition.   Such a definition could guide and instruct research dealing with the relations between neuro-cognitive markers and low achievement.