This paper deals with argumentation coherence, which is determined by relevance, which in turn is determined by the distance and canonicality of references between conclusions. A focus shift occurs when participants choose a conclusion in a new focus to reference, either by supporting, elaborating, continuing or attacking it. This is marked pragmatically by reference to subjects of current talk, thus pronouns referencing the current focus predominate. Scope shift occurs when people consider the debate insufficiently deep or broad, and this is pragmatically marked by references to new (sources of) subjects.