Historians find the relevant stories in primary sources and explain their significance through their relationship to the larger narratives described in secondary sources.  The History Engine, a collaborative teaching tool hosted at the University of Richmond, gives students an opportunity to practice this skill.Students choose a transaction from the day book as the event to describe for their episode.  They use one of the secondary sources we have read to help them determine the larger significance of the event reflected in the transaction.  Episodes undergo peer review and revision, and then the episodes are published through the History Engine.