Hi Shan:

I agree that you should continue to use your method regardless of whether somebody calls it an aftershock (or foreshock), etc.

As you pointed out, the "precursor" may appear and this is for an incoming quake. The definition of it (aftershock) after the fact is not as important as predicting it initially.

Roger's point is well taken as well...that aftershock studies outside S. Ca are not well trodden territory.

Roger's evaluation method should have merit for the "aftershocks" as well...giving some indication of how likely the event was.

In another matter, I think that your claim of a hit for a mag. 4.5 (or so) for a Mag. 6.5 could be scored for "nearness" (as in perhaps as a training aid/feedback ) but is a "real long stretch" insofar as practical use as a forewarning of a quake.

Just my $.02 worth