Advanced Tactical Training was a specialised course of tactical and intelligence training for Starfleet officers. It was a highly challenging course (half those who took it failed to complete the course) and officers wishing to take it had to be recommended by a superior officer. Part of the course curriculum was designed by Elias Vaughn.
In 2255, in an alternate reality, James T. Kirk took part in Advanced Tactical Training. Kirk and Viktor Tikhonov were the captains of Team Delta and Team Alpha respectively in the three ATT mission finals, devoted to First Contact, Security and Science scenarios. Kirk's team performed better in the First Contact final, but Tikhonov's team was victorious in the Security final, the Derelict Cairo scenario. Kirk's team received an extremely positive performance assessment on the Science final, the Tanika Station scenario, from the test's programmer, Commander Spock. (TOS - Starfleet Academy novel: The Delta Anomaly)
Following the completion of the course Ro was reassigned to the USS Enterprise-D where Admiral Alynna Nechayev believed her training made her an ideal candidate for a mission to infiltrate the Maquis. (TNG episode: "Preemptive Strike")