This methodological study concerns the triangulation of two different methodologies, the fine-grained articulation of (1) video data analysis and of (2) self-confrontation interviews analysis. Our objective is to deeply understand what is going on during an activity, to grasp the meaning of the flow of the activity. The two theoretical and methodological approaches combined are on the one hand the Ergonomic Psychology inspired by phenomenology, and on the other hand the Conversation Analysis. We triangulate an intrinsic point of view, the one of the participant describing his/her lived experience, and an extrinsic point of view, the one of the researcher interpreting from the observable actions and discourses. The investigated domain is the interactional activity of users of a carpooling service during rides. More and more services of sharing are proposed, where people need to interact with unknown persons and to build trust for overcoming the potential risks they may perceive. The results bring to light, thanks to the triangulation, three specificities of the carpooling ride: the temporal and normative organization of the conversations in the car, the choice of the place in the car as a collaborative accomplishment for avoiding tension, and the participants’ expectations of framing by the driver. They are exemplified by extracts of videotaped interactions and of explicitating self-confrontation interviews (mixing self-confrontation and explicitation interviews techniques), showing how the fine-grained articulation of both type of data is enriching, how they can match or complement each other, and what kind of phenomena are highlighted by each of them.