Socialization is one benefit of co-op, but they also get an opportunity to learn from other teachers and participate in group projects that just could not happen at home. Our co-op meets once a week for three classes with a snack period between our second and third class. We have classes divided by age or grade and parents take turns teaching the different classes. Over the years we have had some really terrific classes in co-op.
We have studied:
Art of every kind
Fun with Football
My children look forward to co-op every fall. They love the time spent with friends and the unique classes and projects they are able to participate in. I am not concerned in the least that my children are not properly socialized. I know I didn't need co-op to accomplish that, but at least I can mention our participation in social activities to allay the fear of others that have bought into the socialization idea.