<p>Coed by room is every other room side by side is coed and coed by floor is that the floor is split between corridors right?</p>
<p>Well, I don't think I've ever heard your exact terminology, but there are co-ed halls which could be considered "coed by room". I don't think they necessarily alternate but there are guys and girls in the same hall. There are also coed floors with a gender assigned to each hall and then there are some floors that are all same-sex.</p>
<p>thanks for the clarification...I got the terminology from the umich virtual tour site.</p>