Submitting An Extended Abstract To Conference, But Later Changing The Methodology and Research Question
Depends strongly on the conference. It't not unusual (maybe 10% of papers) for presenters to present a paper on a substantially different topic than their accepted abstract at one of the most important conferences in my discipline. That's because it's considered a work in progress and discuss conference, so it's completely accepted that the question you thought about six months prior didn't actually work out.