Telelearning relates to "making connections among people and resources, via communication technologies, for learning-related purposes". Telelearning as a general term includes asynchronous learning activities; in all cases efficiency is an important construct. Efficiency is defined as the relation between costs and effects/quality. An educational system is said to be "efficient" when an optimum balance is found between minimizing the costs and maximizing the effects/quality. This balance is often difficult to obtain, for an example, when the opportunity for direct contact between tutor and tutee through telecommunications facilities can lead not only to beneficial learning and social effects but also to a large amount of messages and a huge time investment by tutors/tutees, leading to an uncontrollable rise in costs. Measuring the effect/quality of telelearning has its own methodological problems and therefore it is difficult to come up with viable and reliable data. How to deal with the efficiency problem is illustrated in the article based upon literature research and data from a recent project executed in the context of the telematics research program of the European Union.