This paper contributes to the discourse in stochastic education of how young students deal with learning settings that allow a data-based approach to probability. By using the micro-structure of arguments by Toulmin (1958), it explores which arguments students use and which role they play in the learning process. The data stems from design experiments with students at the beginning of their stochastic career (aged 11 to 13) and is analysed with an interpretative approach. [For the complete proceedings, see ED597799.]