The great availability of geographic information, due to Spatial Data Infrastructure development, the existence of data collected by volunteers, etc., makes the problems of geometric interoperability of data very conspicuous. Traditionally, conflation is being carefully carried out and evaluated by experts. Yet there are practices that involve occasional users who will look up the information in mobile devices without the intention of keeping a copy. Evaluation will be carried out ?with different criteria, involving the Human Visual System and perhaps even the characteristics of the physical devices ?as well. In this paper, we coin the term 'Ephemeral Conflation' to characterize that context and the procedures to evaluate it.