Argumentation has been the emphasis of many studies during the last decade. However, previous studies have not identified why some students are more successful than others, and what are students' characteristics of argumentation, especially when working collaboratively. The purpose of this study was to identify how young students construct arguments when working in pairs, and hence identify those characteristics of their interactions that might lead students to provide better written arguments in the science classroom. More specifically this study follows a case study design, examining two different pairs from a class of 12- to 13-year-old students that participated in a specially designed instructional approach within a socioscientific issue. The two pairs were videotaped for a duration of four, 50-minute lessons and the transcripts were analyzed in order to identify characteristics of students' interactions during argumentation. The results indicated that one of the pairs constructed high level written arguments by the end of the instruction, and that the two pairs engaged in different types of discussion. The findings suggest that one of the pairs engaged more with the topic, and that a socioscientific context does not afford on its own engagement with argumentation. On the contrary, there is a need of ownership, and engagement that is not automatic and was only evident in one of the pairs. Therefore, an implication arising from this issue for research is an exploration of how students from different backgrounds, either social or cultural, understand and identify with the main socioscientific issues that are used as part of teaching science, in order to understand how to better design curriculum that will support engagement of all students with the topic. (Contains 6 tables.)