All of the following criteria must be met for a diagnosis of a learning disability to be made. – diagnostic criteria for learning disabilities
- A non-random, clinically significant discrepancy between one or more of the specific psychological processes related to learning (phonological processing; memory and attention; processing speed; language processing; perceptual motor processing; visual-spatial processing; executive functions) and otherwise average abilities essential for thinking and reasoning.
- Academic achievement that is unexpectedly low relative to the individual’s thinking and reasoning abilities OR academic achievement that is within expected levels, but is sustainable only by extremely high levels of effort and support.
- Evidence that learning difficulties are logically related to observed deficits in specific psychological processes.
- Evidence that learning difficulties cannot primarily be accounted for by:
- other conditions, such as global developmental delay, primary sensory deficits (e.g., visual or hearing impairments), or other physical difficulties;
- environmental factors, such as deprivation, abuse, inadequate or inappropriate instruction, socio-economic status, or lack of motivation
- cultural or linguistic diversity.
- any other co-existing condition such as Developmental Coordination Disorder, Attention Deficit Hyperactivity Disorder or anxiety.
Note: Learning disabilities may be co-exit with many conditions, including attentional, behavioural and emotional disorders, sensory impairments or other medical conditions.
Clinically significant discrepancy — it is generally accepted that differences of one standard deviation or more between two standard scores based on the same scale reflect significant differences in the attributes measured.
ref: http://www.ldao.ca/