"A distinguishing feature of the Platform Project is that it will follow law enforcement personnel over time to understand their 'life course.' Law enforcement first-line supervisors are one of the populations we are studying because they are key to an agency's performance. Despite their importance, first-line police supervisors have been under-researched, and in many departments they have not received the support and professional development that is needed to promote the highest quality supervision. The Platform will produce data about supervisors and supervision to supplement a sparse literature. A key benefit of longitudinal data collection will be the production of information about first-line supervisors' life course. When officers are promoted to a supervisory rank, they embark upon a new phase of their career requiring a transition to a different role, and as with any job, police supervisors adjust to the requirements of the job over time as they 'learn the ropes' and then mature in the position. Platform researchers will explore how police supervisors develop, determine what influences that development, and discern what the consequences are for performance."