The roles played by Model Three change agents are as varied as those of the Model Two practitioner: negotiator, trainer, facilitator, and, less frequently, diagnostician, expert and judge. Whereas the Model One and Two practitioners must have access to power, the Model Three practitioner must have superior interpersonal skills and be knowledgeable about change principles and strategies. The effective Model Three change agent will know a client system intimately and can identify the points of leverage for change in this system as well as the resources that are to be employed in sustaining change once it has been initiated. While planning for a specific change, one must not only plan for a specific change, he or she must also plan for “unfreezing” the client system, so that it will be open to change and must help “re-freeze” the system so that it will maintain the change that has been enacted. Most change agents make use of a common set of strategies in the initiation and maintenance of such change.
