The challenge of making educational programs accessible to people with disabilities, combined with the increasing emphasis on testing and other forms of assessment, has translated into a need for accommodations in the testing and assessment of people with disabilities. Typically, test accommodations are provided for people with sensory and/or physical impairments, but there is less agreement about test accommodations for people with learning disabilities and other less visible disabilities. Making decisions about test accommodations is challenging because changing testing procedures or materials may change the technical adequacy of a test. Characteristics of technical adequacy include test reliability, accuracy in making predictions about test takers, and test validity. Accommodations allowed in national and state assessment programs are inconsistent, involving widespread variation in practice. A comprehensive set of guidelines is needed that state and national agencies can use in decision making. Guidelines for making decisions about accommodations need to address: inclusion and exclusion criteria, when and how to modify tests or testing procedures, how to report scores, and how to summarize data. Identifying accommodations that are both fair and technically adequate requires a delicate balancing of individual and societal rights. Contains two references. (JDD)