The LEGO CMS Particle Flow Tutorial

The CMS Experiment has implemented the particle flow algorithm as part of its Global Event Reconstruction.  This was a substantial increase in algorithmic complexity in exchange for improved performance.  In order to attempt to counter some of this complexity, and potentially train some new young experts, a tutorial exercise was created using a single simulated event, realized in physical form in blocks representing calorimetry elements, mounted on a cylinder, within which labeled tracks were strung.  At the Large Hadron Collider Physics Center (LPC) at Fermilab, students applied the reconstruction techniques by hand over the course of two days and successfully interpreted the nature of the event.  I will attempt to describe the exercise, and outlook for future such projects.