In this work we present empirical data on the impact of implementing (a) micro-script fade-out and (b) peer monitoring techniques in the context of a web-based argumentation activity in a computer science course. We used the iArgue tool which is a web tool for argumentation incorporating collaboration scripts to structure peer interaction. Additionally, it supports fade-out and peer-monitoring techniques. During the activity students followed the phases of a jigsaw script while micro script support on argumentation faded-out and prompts were activated to remind students to check the validity of their partners' contributions (peer-monitor). Our results demonstrate the feasibility of incorporating argumentation in computer science courses and provide useful information for improved design of fade-out and peer monitoring techniques to support students' argumentation.