Today I was looking over the program and participant list for an upcoming international conference. It's not a huge conference, as it is somewhat specialized, but there will likely be between 70-100 participants.
Here are the current data for this conference:
participants: 75% male, 25% female
invited speakers: 95% male, 5% female
conference organizers: 100% male
The imbalance in invited speakers would be annoying in any case, but the organization sponsoring this conference sent out an announcement saying that it particularly encourages the participation of women and underrepresented groups. I think that must mean that we are encouraged to go to this conference and sit and watch how science is really done; i.e., by men. There happen to be women doing interesting and significant work on the topic that is the focus of the conference, so it is actually really amazing that the organizers didn't invite more.
I don't believe that the organizers deliberately excluded women. That is, I don't think they sat in a room and said to each other "Let's not invite many women to give talks", but I think that they must -- to a man -- not think of women as doing interesting or significant research, at least not with the same level of prestige and rigor as men.
6 years ago