You have to comment on at least six other group members' reflection documents using the Google Document comment functionality (Comment in the Insert menu) before September 17, at 08:00. You may choose which six group members you like, as long as there are at least two from year 1 (prosamm18) and two from year 2 (prosamm17) among them. You also have to comment on a comment in your own document (if there is any). The comments should have some sort of interesting content, not just "I agree".