The state of the evaluation and diagnosis of deaf-blind people: psychological and functional approaches

There has been a raging controversy of long standing in psychology and rehabilitation about how to predict occupational success and other important life outcomes (McClelland, 1973; Barrett and Depinet, 1991). Some practitioners are advocates of psychological tests (Barrett and Depinet, 1991); others argue instead for measures of competence or function (situational samples, job samples, etc.). Assessment is a dynamic process that is still emerging. This concept is often difficult to grasp when confronting the challenges of assessing persons who are severely, multiply impaired. A good illustration of this process may be found in the delivery of services to persons who are deaf-blind. Traditional assessments (i.e. standardized tests) are not productive when used with persons who are deaf-blind. Results are limited because the norm-reference is invalid. Assessments have traditionally focused on predicting outcome. It is noted that there has been a shift from prediction to description in assessment when trying to assess persons who are impaired. This article reviews that process. It calls for the greater utilization of functional assessments which are used: (1) to identify critical behaviors that are present to some degree; (2) use assessments data to develop interventions; and (3) monitor progress over time using an ipsa lateral approach where the person serves as both subject and control.