Command Trainer 4 was a holographic program used for training purposes aboard the USS Cerritos. It was a beginner-level program that was less advanced than the Command Trainer 43 program.
It was used to train new command division officers for service on the bridge of a starship. The program placed the trainee in command of the vessel as it encountered a small asteroid in its flight path. The trainee was expected to issue the appropriate orders to address the situation.
In 2380, Ensign Sam Rutherford used the program under the supervision of Commander Jack Ransom while the former was considering changing careers to the command division from engineering. Rutherford was flustered and unable to issue appropriate orders to the crew. He asked the crew to perform the Janeway Protocol without knowing what that entailed. Due to Rutherford's further inaction, the asteroid struck the ship's kindergarten area, which caused the children aboard the vessel to be jettisoned into space. The breach widened, causing even more children to be lost before the program ended. Rutherford's failure helped persuade him that the command division was not for him, and he moved to the sciences division as another possible career path. Ultimately, he decided to return to engineering. (LD: "Envoys")