This study is conducted as a collaborative study between two researchers and one vocationalteacher in the Industrial Programme at the upper secondary vocational education in Sweden.The study is conducted in iterative cycles and focuses on actual teaching of a technicalvocational object of learning (to make a TIG-weld) in school. The research project is fundedby the Swedish Institute for Educational Research. The study is based on two theoreticalframeworks; the variation theory (Marton & Tsui, 2004) and conversation analysis (Sidnell, &Stivers, 2013). These theories have been used for planning the teaching as well as foranalysing data from the iterative cycles. Combining these two frameworks is a fairly newapproach, but it has previously been done in a few studies (cf. Asplund & Kilbrink, 2018).However, there are no previous action research studies that we know about where thesetheories are combined in the planning of and teaching a specific object of learning. We usethe abbreviation CAVTA (Conversation Analysis and Variation Theory Approach) for thecombination of these theories as a tool in practice-based school research. Inspired by thelearning study method, this study is conducted in three iterative cycles. However, this study isbased on CAVTA as the theoretical framework, in contrast to previous learning studies. Dataconsists of video recorded lessons and audio recorded conversations between theresearchers and the teacher to follow the process of working with this collaborative method inrelation to a technical vocational object of learning. The results from this study show how theteaching content in relation to the object of learning is made visible in the interaction.Furthermore, the critical aspects are displayed more explicitly in teaching over time, based onanalysing, planning and evaluating teaching with a starting point in CAVTA.