This paper explores a new approach to communication science as ‘practical theory’. Three main types of communication science as ‘practical theory’ are analyzed: (1) ‘practical theory’ as mapping; (2) ‘practical theory’ as engagement; and (3) ‘practical theory’ as transformation. Special attention is given to the ways in which ‘practical theory’ is reflected in the following epistemological paradigms: (1) knowledge by discovery; (2) knowledge by interpretation; and (3) knowledge by criticism.