Service in this sense means professionals are those who are educated to serve others and use skills and knowledge that are not common to any person. A teacher uses skills and knowledge that they attain from a degree or other type of education which are not readily available to any man or woman. The second characteristic of a profession Dewey talks about is theory. Theory has to do with knowledge and how we attain it. It also deals with how we teach to others.
Teachers change their teaching habits and practice to achieve new understandings and perspectives.
The third characteristic is practice. Practice is the skills and strategies of the profession. It also deals with where the teaching takes place. Teachers need to always be evaluating themselves and seeing if their strategies are working. Teachers must make certain that they are teaching the material to students in a good learning environment.