The ATLAS detector on the LHC will give us more and more data on particle collisions than has ever before been collected. How do ATLAS scientists select and keep the data that is important to them? In this interview by ATLAS's Steven Goldfarb (U Michigan), Wengler describes in simple terms what the trigger system is and how it works. Subjects covered include the 3 stages of data selection within the trigger system, how many events are kept for analysis and thrown away, how this data is stored, who analyses the data across the world and the importance of constant surveillance of the Trigger system to keep it functioning properly. Produced by: ATLAS OUTREACH Director: Yves-Rene Kayonga Director: Claudia Marcelloni 4:00 min