Animal research: influence of experimenters on results less strong than expectedFor more than ten years now, scientists have been discussing the so-called reproducibility crisis: often, scientific findings cannot be reproduced at a later time and/or in other laboratories, although the studies are carried out under highly standardised conditions. Thereby, standardisation includes for example the use of genetically identical animals, keeping the animals in identically equipped cages, and carrying out the experiments in always the same way.