As a rising senior who took Geology in the Field as my AI, I HIGHLY ENCOURAGE you to take it. So fun, lots of field work dealing with Minnesota's beautiful natural history, and an excellent intro to Carleton's geology department, which is the number one undergrad program in geology in the nation.
As far as FOCUS goes, I asked one of my friends who did FOCUS to reflect on his experiences in it:
"FOCUS is for people that the government considers a "minority" in the sciences. So it is a support group whose goal is for those minorities to love science / pursue science in the future.
When I was a freshman, the perks were:
-You get to choose a science class per trimester before any other student (so you can explore the sciences). BIGGEST plus
-Events that focus on what goes into scientific research and opportunities to speak with Carleton faculty in the sciences. There are also some field trips.
-A group of like minded individuals to hang out with from all years. Older FOCUS students are encouraged to give advice to freshman about choosing majors/ giving advice about classes, etc.
-There are FOCUS specific tutors for classes to help students out (The tutors are other FOCUS students)
-unlike the other AIs, FOCUS is your entire freshman year. Plus it is a group that you can be a part of all four years (which I kinda abandoned after freshman year lol).
-You get like 3000 grant money per year
It is a pretty good program. I didn't enjoy it at first because I didn't want to be considered a minority but I think it is a good program for what it is trying to achieve.
You can contact Eric Egge and Deborah Gross. They were in charge of it my freshman year."
Hope this helps!