This study recognizes the role and the quality of social aspects in collaborative problem solving (CPS) processes and outcomes. The aim of this study, relying on multiple data and phases of analysis, is to explore and visualise, through contrasting case-based portraits, how micro-interaction processes at pair level evolve during CPS assessments in an online environment. The assessment is designed for a student pair in the STEM domain. The results show that in despite students’ similar CPS performance scores, variations in micro-interactions occurred across pairs. It is expected that studying these patterns at pair level may provide new insights into CPS processes and so to support acquiring these skills.