Depends on the age and the class, actually.

I teach second grade and I've done Kagan Cooperative Learning training, and I really like their setup where you seat them in groups of 4 (ideally) or 3 (like if you had 14 students, you'd do 2 groups of 4 and 2 groups of 3). The two toward the board would face each other and then the 2 further from the board would face the board. Ideally you'd also group by ability level--a higher and a lower with 2 middle level abilities.

HOWEVER, you also have to take into consideration how well they behave with each other. This year's class can't be together without talking to each other, so the groups don't really work. I currently have a large aisle with rows of 2 to 3 on each side. My lowest ability level and the students I basically have to sit on to get anything are at the front so I can keep a close eye on them. This arrangement works just fine--this year.

Really, it depends on the group. What works for one group won't work for another.

9 times out 10 the size of the class and the number of students will be determine how you set up the room.

If it is a small number of students I think a half circle facing the board is pretty good. It gives a more warmer energy. if they are looking at each other, it is not you (the teacher) on stage for them but us (the whole class) learning together.

But every school I have seen is so over crowded they have to put students in rows because there isn't enough space to do anything else.

Well, I'm a student so I'll say how I like the desks in my class arranged.

I typically like when 2 desks are side by side and there's like columns. You know?

I like it because you can have a desk partner and well, it's a nice set up.

I hope that helped!

I think that it depends on the class and what you want them to do. If you want them to do a lot of group work, then put them in groups. If you don't want them to talk or interact, put them in rows. If your class does a lot of discussion, put them in a big circle.