QUOTE(Lking @ Oct 19 2007, 05:56 PM)

...Assuming correct calculation, which may be at issue, skewed how? A change to a moving average or a report count isn't a lifetime average. Different numbers represent different things. Which calculation is appropriate does depend on what intent IronPost had when the number was included.
Evidently the simple equation (sum of ages on reporting)/(total reports) gets broken on occasion by errors in either/both the numerator and/or denominator. That skews the result which is intended to be the simple average of reporting time. Uncharacteristic input (such as an atypically old report) also skews the result although that should generally be a minor effect, given the restriction on the age of reports accepted for processing and the large, "lifetime", size of the denominator. But we know something occasionally goes astray and "impossible" results ensue. And we know the age on reporting, as seen during the parse, is variable depending on whether mailhosting is set up or not - which raises the whole question of "age".
The figure/"statistic" that would (logically) be of significance to Cisco/IronPort/SpamCop is the total number of reports submitted, it underlies the whole "user reporting" adjunct to the SCbl operation and represents the "product differentiation" of the SCbl. Don, on at least one occasion (IIRC), has demonstrated "here" the ability to cite this figure in relation to an individual reporter. Whatever the intention behind providing the users with the average reporting time it was, I think, enabled by the retention of this (denominator) factor as a matter of SC's vital concern.
IF (big supposition) the statistic is available, requests by reporters to provide it routinely (whether as well as or in place of the average reporting time) have been ignored. If Cisco/IronPort/SpamCop had any intention of restoring the credibility of the average reporting time figure they would provide it to eliminate or confirm that factor as the the principal problem in the equation. The fact they do not, to extend the chain of supposition, indicates to me that they probably do not wish to have it so closely scruitinized. Which would be bad news for Cisco/IronPort top management who probably rely to some extent on the accuracy of its aggregate value. (Yes, I know I'm cruel, Wazoo reminded me of that ages ago

but it was not news even then.)
A neat way to sideline the accuracy issue would, indeed, be to restrict the average reporting time calculation - say to the 90 day period of user reporting history. Yes, this would represent a formidable processing overhead, truly, it would no longer be a "lifetime" measure - but it would reflect "current" user and system processing performance which might be at least as relevant to a greater number of reporters, especially given that the "long count" has little/no credibility in their eyes. Any errors would fairly quickly work their way through the count to be excreted into oblivion after (say) 90 days. If any such errors might be comparatively magnified, because of the comparatively low denominator, they will at least be highly visible - giving the opportunity for identification of the cause(s). But I think they're probably quite infrequent on any sensible timescale.
I'm surprised SC hasn't hit on this "solution" already, and implemented it with gleeful cries. I can only suppose my chain of supposition is faulty somewhere. Or the engineering staff have more pressing concerns (where's the emoticon for "just a touch ironic"?). Or both

IMUO - in my uninformed opinion.