Ethnomethodological research involves participation in the field, with some degree of social interaction, with the subjects of the study; direct observation of relevant events; some formal and a great deal of informal interviewing; systematic counting; collection of documents and artifacts; and flexibility in the direction the study takes. This paper begins with criteria for the reliability, validity, and quantification of ethnomethodological research in professional education. The field training of rookie police was observed and analyzed by means of ethnomethodological research. After 16 months of observing field training instructors, it was reported that a particular body of knowledge was shared and expressed in the work of all competent members of the profession. This knowledge, composed of attitudes and skills, was demonstrated by the officers who acted as teachers and models to the probationary officers assigned to them during field training. These attitudes and skills were communicated both verbally and nonverbally. Field training officers evaluated the rookies by means of a checklist of practical job skills. (Author/BH)