Conversational Case Based Reasoning (CCBR) is a form of CBR where users initiate conversations with the system to solve a certain problem. Current CCBR solutions are limited to specific domains. In the solutions we find a lack of flexibility to deal with the user’s variability: different conversation strategies depending on the user’s current mood, computer skills, and domain expertise. We focus our framework, COBBER, in the user’s variability during a computer session. COBBER is a CCBR framework to build CCBR applications in a systematic way. The framework offers, independently to the domain, models of different conversation strategies using causal loops.