Although the terms assessment and evaluation are often used interchangeably, they have different meanings. Evaluation is a process that begins with a review of existing data and ends with a determination of eligibility. [See 34 C.F.R. § 300.305(a) and A.A.C. R7-2-401(E)(3)] Evaluation is defined in the IDEA regulations as procedures that are used to determine whether a student has a disability and, if so, the nature and extent of his/her need for special education and related services. [34 C.F.R. § 300.15] The Commentary to the IDEA regulations echoes this by stating that an evaluation under the IDEA refers to the process for determining eligibility for special education and related services. [34 C.F.R. Part 300, Analysis of Comments and Changes, Subpart D–Evaluation, Eligibility, IEP, Educational Placement, Federal Register, Vol.71, No. 156, p. 46639 (August 2006)] Additionally, the IDEA regulations specify that evaluations may, among other things, be used to determine whether additions or modifications to a child’s special education and related services are needed. [34 C.F.R. § 300.305(a)(2)(iv)]
Assessment focuses on teaching and learning, and provides information for improving learning and instruction. Assessment information is used by teachers to make changes to the educational environment, and assessment is shared with students to help them improve their learning.
An example regarding independent educational evaluations (IEEs) points out the difference between what might be considered an evaluation and what might be considered an assessment by analogy. The purpose of the appraisal performed becomes critical in determining whether parents are entitled to an independent educational evaluation (IEE) when they disagree with the results of that appraisal. If the purpose of the appraisal is to determine the presence or absence of a disability or to evaluate the nature or extent of a student’s need for special education and related services, it's considered an evaluation and the parent would be entitled to an IEE if they disagreed with the results of that evaluation. If, on the other hand, an appraisal is carried out to inform the present levels of academic achievement and functional performance and/or to develop measurable postsecondary goals in the IEP (and does not result in an evaluation), the parent would not be entitled to an IEE.