I've read a couple of articles that look at girls who come up in schools for girls and women who attend colleges for women, etc.
I know there are a number of women-only dojo out on the west coast. I've never visited one, never trained at one. A few years ago the women from our dojo used to meet on Sundays for workouts together.
Do folks have any experience in single gender settings? Good, bad, indifferent?