I've been working on something recently that has me following up on the conference literature-- I've been tracking down conference papers on a particular topic to see what the latest word is. Anyway, one thing I've found is that a seemingly highly active new Ph.D. has given roughly the same paper under different titles at (by my count) eight different conferences.
Now, I confess to having given pretty much the same conference paper on two or three occasions, but this was always with the intention of revising and reworking in light of comments and questions. But I somehow arrived at the view that three is the limit for a conference paper. (Colloquium presentations are a different story-- they evolve over time, and sometimes one gets multiple invites to talk on the same topic, etc.) Is the three-conferences rule unreasonable? Is three too many? Am I right to think that eight is too high?