This study focuses on how to support students who have to work together in small groups, and who do not know each other, in performing grounding discussion. It compares two different implementations of a script, one using a structured interface, one using a textual instruction, on students' discussion behavior. The experiment involved two grounding discussions that were performed by 42 students from several countries, working together at a distance in small international groups of four to six students. Our main hypothesis was that the script would lead to better grounding discussions, and that the structured interface would strengthen the effect of the script. Several qualitative and quantitative analyses showed that (1) the script led to more and longer input to the discussion, more discussions, and the structured interface led to even longer inputs; (2) the script led to more effort on the grounding discussions, compared to other course components; and (3) the script led to better adherence to the order of course components, with the structured interface having an additional effect.