FemaleScienceProfessor writes that her mother — who is neither a scientist nor an academic — recently asked whether she gives the exact same talk at various conferences. When FSP responded that she did not, she writes that her mother asked "But why not? The people who live in A/B weren't at your talk in X/Y, so you could give the same talk." In a related post, FSP says that she "listened to a 'famous scientist' give the exact same talk that I had heard him give at a conference a few years ago," which surprised her since the talk was not an invited review and it was part of a session wherein "it was reasonable to expect to hear results of new research, not a rerun." FSP says that it's common for a researcher to give a talk at a small conference, and then repeat it at a larger conference — though it's the general case that they "make the second talk a bit different." However, giving the exact same talk in different years at the same conference, FSP says, is less tolerable. She asks whether "the session convener had reason to know in advance that 'famous scientist' would present that same old stuff, would it be so bad to give him a poster and give a talk slot to some up-and-coming scientist with new results?"
In a comment to the FSP's post, blogger PhysioProf links to a related discussion at Ann Little's Historiann blog. Little writes: "I'm looking for spankin'-fresh ideas at professional conferences, not three-day-old leftovers from Dr. Ripoff. Besides, how boring for the presenter to be rehashing stuff he had already worked out."