Stress drop is a fundamental earthquake source parameter that in theory relates the average slip on a fault to rupture area, and in practice characterizes the high frequency seismic radiation. It is a key parameter in earthquake ground motion modeling, rupture simulation, and analysis of source physics. However, stress drops are notoriously variable and difficult to measure; estimates by different researchers, using different methods or datasets, yield highly inconsistent values which may mask physical trends. In this session, we seek to bring together researchers from across the community to compare and validate stress drop estimates, source characterization and high-frequency ground motion. We particularly encourage analysis of the 2019 Ridgecrest Earthquake Sequence and any comparative stress drop or source characterization studies. We hope to understand the physical controls and methodological reasons for similarity or differences in stress drops, so that they can be used reliably by the earthquake science community.