A model was developed to identify the communicative tasks that are most likely to facilitate successful consultation. Three distinctive features of process consultation were considered important to the model: the focus on the human element of the system, joint diagnosis between consultant and client, and the passing on of diagnostic skill. To validate the model, interviews were conducted with seven consultants and observations were made of the work of three consultants. The model of the communicative tasks used in process consultation includes: the contact, scouting/relational escalation, diagnosis, planning, implementation, evaluation, relational de-escalation, and termination. Findings that agreed and differed with the literature on the subject were noted. Effective communication and persuasion were empirically confirmed as critical and central requirements in process consultation. (MKM)