When new educational technology is put into actual use, new ways of using the technology and new ways of organizing instruction can emerge. A critical feature of formative research conducted in actual settings is that the organization of instruction can change as the educational environment appropriates the technology to its own goals. Thus, the task of design goes beyond the design of the technology to consider how the new goals can enter the technology-environment system. The formative experiment is a method by which changes in goals and uses that occur when a new piece of technology becomes part of an educational environment can be tracked. The theoretical basis for this method is appropriation, in which the teacher appropriates the students' actions into her own way of understanding the task, finds a way for students to play at least a minimal role in its accomplishment, and gives feedback in terms of the expert understanding of the task. Specific examples illustrating the method's application include a Local Area Network environment designed for collaborative school work and intelligent instructional systems for use in training specific technical tasks. (34 references) (GL)