Publicly organized challenges provide a unique opportunity to bring a research community together to gain a quantitative and unbiased comparison of a diverse set of methods applicable to a particular data‐processing task. Such publicly organized challenges have helped to establish a common ground for the evaluation of competing methods in a variety of imaging‐related tasks, e.g. in brain MR image registration45 and segmentation.46 In DW‐MRI, public challenges have focused on recovering synthetic intra‐voxel fibre configurations47 or evaluating tractography techniques48, 50 and have been very successful at driving research and translation forward. Another interesting comparison of reconstruction methods using DW‐MRI data was based on the signal acquired from a physical phantom.49 Here we report on such a community‐wide challenge to model the variation of DW‐MRI signals at the voxel level in the in vivo human brain.