Over in the department of Basketweaving, they're advertising for a Visiting Assistant Professor of Basketry. Then one of my students asked what it means, a visiting assistant professor.
So, I thought I'd test the waters and ask about your experiences with VAP sorts of stuff.
Here's what I've seen myself.
Some are rotating positions, where the school has decided it doesn't have adequate funding for tenure line positions, but it's pretty sure it can fund a position for a couple years, and probably a couple years after that, and then they'll see, based on demand and such, and maybe continue. For the administrators, this means a smaller paycheck, and probably smaller benefits. (The health insurance will be the same, but there will be a lower cost for retirement benefits, if they're included, based on the VAP's salary being lower than a TT salary. And so on.) By doing a VAP thing, the school can bring someone on board with a terminal degree, who might not otherwise be available nearby. (This is important for more rural schools, for sure.)
Some are sabbatical replacements, perhaps. Those are usually advertised up front for one year.
Some are planned leave replacements. For example, if a member of a small department has found a different job, but isn't sure they really want it, they might arrange a leave of absence for a year. They go off to the new job, and if they don't like it, they return, and if they like it, they tell the department they won't be back. If they come back, the VAP was a one year position. If they don't come back, then it might be too late to do a full search by the time they inform the department, and the department might use a VAP for a second year.
Some are unplanned leave replacements. NWU did this with a position for a year, when someone here got really sick. The person was well liked and greatly respected, so no one wanted to hire a new person permanently for the position (even if they could have, legally). But no one knew whether the person would have really successful medical treatment, or not. Similarly, if someone who wouldn't be expected to leave takes a leave of absence because there's a family difficulty, a school might use a VAP to fill in.
What other situations do you see VAPs advertised to cover?