A Report on the Third Meeting of the Open Reflectivity Standards Organisation (ORSO)

The Open Reflectivity Standards Organisation is an international and open effort to improve the scientific techniques of neutron and X-ray reflectometry. It is an open and welcoming collaboration focused on improving international standardization in those techniques. This new collaborative network of scientists was established at an initial meeting at the end of 2019. That meeting created four working groups that concern different aspects of reflectometry: File Formats, Reproducibility, Data Analysis, and Education and Outreach. Despite the global pandemic, ORSO has been steadily building on those foundations. ORSO met for the third time in June 2021 with 120 registered participants from neutron and X-ray largescale facilities and from academia around the world. For the second year running, the meeting was held virtually with sessions accessible to all time zones. The meeting was spread over 5 days but began with two plenary sessions with talks from a range of international experts on reflectometry. On the final day, the meeting was closed with a final plenary session that looked to the future with three talks on the application of Machine Learning or Artificial Intelligence to Reflectometry. In between these sessions, each of the working groups ran a series of sessions covering their own scope, as outlined in the following.