Train the Trainers (TTT) model is intended to engage master trainers in coaching new trainers that are less experienced with a particular topic or skill, or with training overall. TTT training can build a pool of competent instructors who can then teach the material to other people anda new participant typically gets to watch an experienced trainer teach, complete the exercises, and then practice teaching segments to other participants. The master trainer and trainer participants should use the CDC Professional Development (PD) Best Practices.