Q: How should I write a conference paper abstract for an already published method?
I have written a conference paper that suggests method A to solve problem B. The paper evaluates the method for just one time instant. Now, I want to publish another conference paper that mentions the behavior of method A for problem B over time. Should I mention in the abstract that the method has already been published?
Your new paper seems to be a follow-up to your previous paper. So, you will indeed need to mention this in the abstract of the new paper for both scientific and ethical reasons. As this is an abstract, you can add why you chose to do a follow-up study, that is, why you felt it was necessary to study the effect of method A on problem B over time. This is to evoke interest in your paper, especially to those who may be familiar with your earlier paper. In the main paper too, you can talk about why you felt this was necessary.
Related reading:
This content belongs to the Conducting Research Stage