Roger,

Have you ever heard of close only counts with horseshoes and handgrenades? I'd put earthquakes in the handgrenades category. Aside from that, here are some other reasons.

1) As with any other study, deviation from expected results is acceptable. It basically boils down to what is acceptable deviation though. You've already seen what is acceptable to me from previous posts.

2) Reported magnitudes are only an educated guess and an average of all the reported magnitudes. There are also various scales for reporting magnitudes. Which one do we use? Which one is right? Also, as we all know, one scale is better for one size of quake then another. Are we getting the right scale for that particular quake on the lists? For instance Mb is only good for quakes up to M7, then it starts getting saturated.

3) Reported magnitude scales are measuring what happens during an earthquake. Predictors are measuring some anomoly prior to the quake that is far different then what the magnitude scales are reporting and trying to get close to those scales. Question, though, is what scale is the appropriate scale to measure the prediction against. Should all of the scales be used and a hit allowed for a hit on any one of the scales or should some other method be used to measure the success of the prediction?

These are some of the reasons for my use of the word "subjective" concerning the table Michael was doing.

BTW, I am also a mainframe programmer (can we say dinosaur?) which I've been doing since 1977. The last 8 years I've been filling the role of a Database Administrator using IBM'S DB2 on the mainframe for various HR types of systems. I'm also 6 months short of hitting the big 50.

Dennis