Embodiments order observed beacons based on relative signal strength to create a correspondence between beacon sets and positions. A computing device such as a mobile device provides a positioned observation including a plurality of observed beacons and a position of the mobile device during observation. The observed beacons are ordered based on quality indicators such as signal strength relative to each other. A set of the beacons are selected based on the ordering (e.g., the beacons with the strongest signal strength are selected in order). The position of the observing mobile device is associated with the beacon set to enable location inference for other devices providing observations including the same beacon set.