This paper evolves around the challenge of ensuring sufficiently guided learning on one side and self-directed, learner-centred learning on the other side. An online course using collaborative case-based learning is taken as an example to discuss tradeoffs between designing collaborative processes upfront and the need to allow for emergent, unspecified forms of collaboration. To do so, collaborative learning is conceptualised as being influenced by three different kinds of logic: formal, informal and practical. Examples for scripted, polychronic and improvised interactions are to illustrate the interplay between the three kinds of logic.