While interaction in online language learning in the area of written computer-mediated communication is well researched, studies focusing on interaction in synchronous online audio environments remain scarce. For this reason, this paper seeks to map the nature and level of interpersonal interaction in both online and the face-to-face language tutorials used at the Open University, UK. A coding system for mapping interaction against the tenets of SLA is proposed and applied to sample tutorials. Initial analyses of data reveal differences with regards to the level of student participation, the use of the target language (L2) and the degree of tutor control and focus. (Contains 2 tables and 8 figures.)