Tutors have only limited time to support the learning process. In this paper, we introduced a model that helps answer the questions of students. The model invoked the knowledge and skills of fellow students, who jointly formed an ad hoc, transient community. The paper situated the model within the context of a Learning Network, a self-organised, distributed system, designed to facilitate lifelong learning in a particular knowledge domain. We discussed the design of the model and explained how we selected and supported capable peers. Finally, we examined the calibration of the model and a simulation, which was intended to verify if the model is fit for use in experiments with students. The results indicate that, indeed, it is possible to identify and support capable peers efficiently and effectively.