Even though standardized test scores should not be used to determine or diagnose disability, quantification is required to demonstrate that a child should receive services. Depending on the district, city, and state laws, a child with a certain percentage of delay in one or more domains is eligible to receive related services or to be placed in special education. It is the evaluator’s job to use his or her clinical judgement to determine percentage of delay if it exists.
The evaluator should learn to interpret a mild to moderate delay as 25% delay and a moderately severe to severe delay as 33% delay. The amount of delay determined should be in the context of the child’s community. Therefore, it is essential that the evaluator be familiar with typical development for that community to know if he or she is delayed and if so, how much. This knowledge is also called clinical judgement or informed clinical opinion.
Examples of quantification without using test scores:
“Based upon the assessment materials administered and clinical judgment, this 3;4 month old child appears to be functioning at the 24 to 30 month level in receptive and expressive language, indicating at least a 25% delay.”
“Based upon the assessment materials administered and clinical judgment, this 4;0 month old child’s cognitive skills appear to be in the mildly to moderately delayed range, evidencing by at least a 25% delay.”