- Time span: The AMS/ASL meeting has only been an annual occurrence since 1995, so I'll take that as my starting year.
- Types of talks: The only talks I know of at AMS/ASL meetings since 1995 are plenaries, so that's easy! Again, I'm including speakers who were invited to give a talk, accepted the invitation, and then couldn't attend since the goal is to study who is invited, not who is invited and not prevented from attending.
- Numbers v. proportions: Once again, I'm going to argue for studying the proportion rather than the number. The 2 female speakers out of 10 in 2004 and the 2 female speakers out of 6 in 2009 don't demonstrate the same level of representation.
Looking at a LOWESS (locally weighted scatterplot smoothing) plot helps a lot in making sense of this data: representation was not horrible in the first two years, it tapered off to almost nothing for about a decade, and since then, there have been some better years and some very bad ones.
Summary: I'm not going to comment on the linear regression because that doesn't seem to be a reasonable model at all. Representation of women fell and then stayed extremely low for about a decade before beginning to increase again, but even the improvement since 2007 isn't stable: in six of those years, representation has been at least 28.6%, but it has dipped down to 0% in three rather regularly-spaced years.Next up: the APA/ASL meetings!