A method comprising: obtaining test data collected on a test track at a particular site, the test data comprising a plurality of radio samples and for each radio sample an indication of a reference location, each radio sample including at least one characteristic of at least one radio signal transmitted by at least one beacon and measured by a mobile device (311, 312, 600) at the indicated reference location and an identification of the at least one beacon; estimating for each of a plurality of representations of a radio environment for the particular site positions on the test track based on the plurality of radio samples of the test data and on the respective representation of the radio environment, wherein each of the plurality of representations of the radio environment has been generated based on a different selection of a plurality of batches of fingerprints, wherein each fingerprint comprises a radio sample and for each radio sample an indication of a location of measurement, and wherein each radio sample of a fingerprint includes at least one characteristic of at least one radio signal transmitted by at least one beacon and measured by a mobile device (311, 312, 600) at the indicated location of measurement and an identification of the at least one beacon; determining for each of the plurality of representations of the radio environment a positioning performance by comparing the positions estimated for the respective representation of the radio environment with the reference locations; and determining, based on the determined positioning performances, whether one or more of the plurality of batches of fingerprints are to be excluded as a basis for a generation of representations of the radio environment for positioning purposes and/or selecting a representation of the radio environment resulting in a best positioning performance as a currently valid representation of the radio environment for the particular site, characterized in that a respective batch of fingerprints comprises fingerprints collected by a single mobile device (311, 312, 600) such that fingerprints from different mobile devices (311, 312, 600) are generally included in different batches of fingerprints. obtaining test data collected on a test track at a particular site, the test data comprising a plurality of radio samples and for each radio sample an indication of a reference location, each radio sample including at least one characteristic of at least one radio signal transmitted by at least one beacon and measured by a mobile device (311, 312, 600) at the indicated reference location and an identification of the at least one beacon; estimating for each of a plurality of representations of a radio environment for the particular site positions on the test track based on the plurality of radio samples of the test data and on the respective representation of the radio environment, wherein each of the plurality of representations of the radio environment has been generated based on a different selection of a plurality of batches of fingerprints, wherein each fingerprint comprises a radio sample and for each radio sample an indication of a location of measurement, and wherein each radio sample of a fingerprint includes at least one characteristic of at least one radio signal transmitted by at least one beacon and measured by a mobile device (311, 312, 600) at the indicated location of measurement and an identification of the at least one beacon; determining for each of the plurality of representations of the radio environment a positioning performance by comparing the positions estimated for the respective representation of the radio environment with the reference locations; and determining, based on the determined positioning performances, whether one or more of the plurality of batches of fingerprints are to be excluded as a basis for a generation of representations of the radio environment for positioning purposes and/or selecting a representation of the radio environment resulting in a best positioning performance as a currently valid representation of the radio environment for the particular site, characterized in that a respective batch of fingerprints comprises fingerprints collected by a single mobile device (311, 312, 600) such that fingerprints from different mobile devices (311, 312, 600) are generally included in different batches of fingerprints.