This study investigates the role of a collaboration script, the Funnel Model, in supporting students' computer-supported collaborative scientific argumentation, and how the students appropriated the collaboration script in scientific argumentation. In this exploratory case study, a class of 33 Secondary grade four students went through four phases of computer-supported collaborative argumentation activity scripted by the Funnel Model: individual ideation, intra-group synergy, inter-group critique and intra-group refinement. Multiple sources of data were collected including student-generated artefacts online at different phases of collaboration, and the post-intervention interviews with the students. The results show that the Funnel Model facilitated students' computer-supported collaborative argumentation. The students' levels of content mastery, motivation, classroom culture and time allocated for classroom participation affect students' appropriation of the script for effective collaborative argumentation.