Needs assessment almost always focuses on the assessment of change, change from the real to the ideal, present to future, actual to expected, and so on. As a result, most definitions of need can be represented by a mathematical-style change formula. However, most presentations of the concept of change do not completely represent the complexity of the actual needs assessment process. In contrast, field analysis is the process through which changes in a system and its environment are clearly described, so that these changes can be judged to represent either needs, opportunities, or costs. Some of the steps in conducting a field analysis include: defining the field, determining the change to be considered, characterizing the change, and appraising the change. In this view, needs assessment is a subject of field analysis. (Author/CM)