Improv directors are sort of like improv 'coaches'. They help direct the group into a good direction, guide them, and help them practice. They also give them notes after a show for an objective perspective. Del Close, for example, would be considered an improv director... right?

Nope, I would say Del Close would be an improv coach, as well as anyone who helps an improv team practice or "guides them". Directors are for directing actual things that will occur during the show or performance. So it's correct to question why that word is being used for improv.

I'm pretty sure Ryan's right. Especially if they're working on a specific improv form (and not just a "Go be funny for 20 minutes!" sort of thing), the person would be called a director since they're helping to shape and create the entire form. I think a coach is more of someone who leads exercises that help with improv in general. A director is someone who is specifically working on this show/form.

Also, for that particular show, it is some sort of dance thing, apparently. Which could also be the reason "director" was used, since it's not just your run-of-the-mill improv show.

The word director can be taken in a couple meanings with improv. Most often, it's used to describe what is essentially an artistic director... someone who is responsible for the format, adherence, individual and group growth, notes, etc. This is someone who is a consistent entity among the group, as opposed to a coach, that could be for a day, week or longer.

A lot of times, the name becomes interchangeable with coach, the same way that rehearsal is with practice. You don't really rehearse as there isn't material, you develop skill... so practice is probably the most appropriate term. As in the same, there's no blocking or line delivery to direct, so coaching may be better used.

The combination of semantics vs. vision / continual guidance is how we see this title time and again.