The study focuses on strategies for how online course outlines can be designed to improve the use of collaborative peer feedback in distance education and how distance students can learn to use argumentation processes as a tool for learning. For ten weeks, 30 student teachers studied the web-based 15 credit course Teacher Assignment. Data was collected from five student groups' asynchronous argumentation, relating to authentic cases of teacher leadership. Focus was placed on the extent to which students used own and others' texts meaning content in the discussion forum and how the content can be analysed. A close investigation of the dialogical argument patterns (N=253) in their peer feedback shows the extent to which students distinguish, identify, and describe the meaning content that emerges in collaboration with other students in an online setting as an important aspect. The dialogue patterns that developed are illustrated in selected excerpts.