Over the past few months I've become obsessively interested in skirt length. I'm finding it hard to get my head round the fact that skirts were microscopic - even telescopic - at the all-girls' school I previously worked at. Yet almost every girl wears trousers at the mixed school I now teach in.
A quick survey of fellow teachers confirms that this is a national phenomenon. Why?
Who are the single-sex school girls trying to impress? Why are short skirts on grammar school girls seen on a sign of character? Why is it that as soon as one or two mixed- schoolgirls sport skirts, memos fly round referring to inches and knee-caps? Why, why, why?
When I switched from working in an independent girls' grammar in the Midlands to working in a mixed high school in Kent, many of the differences were intriguing.
No. I cannot lie. Many of the differences were Insomnia inducing.
My role as form tutor in my first school was to act as a big sister-style agony aunt and listen, nodding wisely, to problems with friendship and family. Now I act as referee and umpire as, at precisely 8.35 every morning, the brawls begin. Despite my cunningly constructed seating plan, there are just not enough corners in my room to separate the hops who cannot sit next to each other without coming to blows.
I have to admit that most of the time I do not mind this.At least white they're fighting with each other they are not setting fire to deodorant cans under the desks or smearing lovingly prepared egg mayonnaise sandwiches in artistic patterns on the floor.
Both these incidents occurred when I was still naive enough to consider quietness in class a good thing".
Many of the gender-hosed assumptions that I held when I arrived at my mixed school have hem shattered. Despite the impression my tutor group tries to instil in me, naughtiness is not the sole preserve of boys. I could introduce you to girls capable of matching boys every step of the way in whichever branch of delinquent behaviour you care to mention.
Then there are the myths spread about boys in lessons, especially English lessons. I know two: the traditional boys dominate the discussion one; and the slightly more trendy boys opt out of involving themselves in anything requiring literacy, literature, emotions and discussion.
I've found neither is true.
But one thing I realty have learnt is that, above all else, pupils are individuals.
On balance, if I had a daughter, I'd send her to join the trouser-wearing girls of the mixed schools. Whatever else they may leave secondary school with, it certainly won't he illusions about the opposite sex.
Joanna Williams teaches English in a mixed high school in east Kent.