There's no keeping up with what teenagers think is in or out; status changes by the minute. But when you develop computer-based instruction (CBI) for that population of users, you'd like to know with some reliability that the program is in. At the least, you'd like to know that users won't respond by rolling their eyes. Such was the case with a CBI program designed for a nonprofit organization that demonstrates the firing of a civil war cannon for middle school and high school students. The organization wanted to distribute a CBI program to schools so students would have background knowledge about the cannon before watching the firing demonstration. The program designer decided on a character-mediated approach to instruction, with the character being modeled after the man who performs the demonstration. That man is a jovial older man who wears a beard and a replica of a Union uniform; the CBI program character, called Sarge, is a line drawing in his likeness.