Gosh, thanks for the lively discussion everyone; let's keep it civil and informative, please.
Obviously this is an issue that needs to be discussed with tact, and perhaps that's why it isn't talked about enough. As a male, and fairly fresh teacher, I'm coming at the issue from a male perspective, so I really appreciate all of you giving your own perspective on the matter.
A specific point someone raised was that the term 'woman' rather than 'female' with be preferred. I went with the more clinical term because it avoids needing to switch from the term 'girls' to 'women' at some predefined age limit. Do you think it would be better to refer to 'women' for all age groups?
With regards to harassment, if girls are put off by boys in classes when they're younger, and they 'see' Physics as a mainly male subject leading to male dominated industries, I can see how that could discourage them from choosing it. We do find that girls in single sex schools are much more likely to study Physics. They could be considering sexism and the potential barriers in the field due to their gender, or it could be somewhat childish instincts. We do expect 16 year old's to make decisions that arguably set them on their whole career path.
Despite attempts to open doors and provide female role-models over the last 25 or so years that 20% (of Physics students being girls) figure has remained fairly constant. I'm interested to know what a green Physics teacher on the ground can do to give those potential Physicists a fair chance.
Thanks again for all of your comments. Please do share the survey link if you know someone who's like to contribute.
EP