Preschool Categories According to Arizona Revised Statutes 15-761: 

"Developmental delay" means performance by a child that is at least three years of age but under ten years of age on a norm-referenced test that measures at least one and one-half, but not more than three, standard deviations below the mean for children of the same chronological age in two or more of the following areas: (a) Cognitive development. (b) Physical development. (c) Communication development. (d) Social or emotional development. (e) Adaptive development. The results of the norm-referenced measure must be corroborated by information from a comprehensive developmental assessment and from parental input, if available, as measured by a judgment based assessment or survey. If there is a discrepancy between the measures, the evaluation team shall determine eligibility based on a preponderance of the information presented. 

"Preschool severe delay" means performance by a preschool child on a norm-referenced test that measures more than three standard deviations below the mean for children of the same chronological age in one or more of the following areas: (a) Cognitive development. (b) Physical development. (c) Communication development. (d) Social or emotional development. (e) Adaptive development. The results of the norm-referenced measure must be corroborated by information from a comprehensive developmental assessment and from parental input, if available, as measured by a judgment based assessment or survey. If there is a discrepancy between the measures, the evaluation team shall determine eligibility based on a preponderance of the information presented. 

"Speech-Language Impairment" for a preschool child means performance on a norm-referenced language test that measures at least one and one-half standard deviations below the mean for children of the same chronological age or whose speech, out of context, is unintelligible to a listener who is unfamiliar with the child. Eligibility for a preschool child under this subdivision is appropriate only when a comprehensive developmental assessment and parental input indicate that the preschool child is not eligible for services under another preschool category or under the developmental delay category. 

"Hearing impairment" means a loss of hearing acuity, as determined by evaluation pursuant to section 15-766, which interferes with the child's performance in the educational environment and requires the provision of special education and related services. 

"Visual impairment" means a loss in visual acuity or a loss of visual field, as determined by evaluation pursuant to section 15-766, that interferes with the child's performance in the educational environment and that requires the provision of special education and related services.