Optimization of data quality and reproducibility are timely and crucial to ensure high-quality research in molecular-scale biophysics. WG4 aims to work towards establishing standard tests to guarantee sample quality, setting up standard operation protocols (SOPs) for both established and new techniques, and developing new standard reagents and methods suitable for modern biophysical techniques. Moreover, WG4 carries out multi-laboratory benchmarking studies improving reproducibility and comparability of different techniques. Being part of an open style network WG4 combines the input from many labs (academic and industrial) and instrument developers. All outputs are freely shared within our network and made publicly available, laying the cornerstone to improve scientific research.