Diagnostic, placement, and curricular decisions are frequently made based on limited, rather subjective information (Kauffman, 1997).

Current assessment practices related to the determination of eligibility for disabilities are heavily influenced by legal requirements, as noted in Chapter 6. These requirements determine the kind of assessment that must be provided to all students considered for special education, including LD, MR, and ED. Compliance with these legal requirements is prompted by professional ethics and federal and state compliance monitoring activities, which typically focus on sample cases of students placed in special education. During these monitoring activities, careful scrutiny of the assessment practices and the domains of behavior examined establishes strong incentives for school district personnel to follow general assessment requirements and specific disability classification criteria, although at least some studies suggest that the criteria are applied loosely, especially in the determination of LD.

The typical assessment battery for nearly all students with disabilities includes the administration of a comprehensive, individually administered test of current intellectual functioning (IQ test), an individually administered general achievement test, classroom observation of student behavior, and one or more behavioral checklists or rating scales typically completed by the teacher or parent. In some regions, various tests of underlying processes are utilized (e.g., visual-motor, auditory processing). This battery is used with virtually all students with disabilities. The only exceptions occur with students with severe or marked sensory disabilities, which may render psychological and educational assessment impossible. Medical specialists typically diagnose students with severe disabilities of these kinds, and special education eligibility determination is not the primary focus of the evaluation.

The relative emphasis placed on the domains above—that is, current intellectual function, achievement, and behavior ratings—depends on the disability that is being considered by the multidisciplinary team. For students considered for the diagnosis of LD, there typically is in-depth consideration of achievement in one or more of the domains identified as problematic in the referral. For example, for a student referred due to low reading achievement, administration of several reading tests and additional formal and informal assessments of reading skills are likely in order to establish more precisely the degree and nature of the reading difficulty. Depending on state classification criteria and local practices, students considered for LD may also receive one or more tests of underlying psychological processes. Currently, measures of phonological processes are nearly