Weapon Affinity

[Derrict]

1.0% margin of error on the longer parses, 1.78% on the shorter parses.

I think you're underestimating the errors a bit. Im finding the error in the total ppm's to be rougly +/-0.2 ppm, or 2.5-4%. If you assume that WA does give 10% per level, then the WA2 data is just on the edge of the 95% confidence interval, the others are well within margins.

Depends what basis is used to determing the margin of error.  I'm using the total amount of procs (ppm x duration = total procs).  

Parse 1, 653 minutes, 5.695 ppm, 3719 total procs, or 1.63%.

Maybe I'm missing something here but if I'm doing  a parse on procs, I'm going to use the total number of procs as the basis for margin of error.  If I'm doing a parse on +accuracy, I'm going to use the total number of hits / misses as my basis.

Like I've stated in the past, if you don't like the data, you can always do it yourself.

[Coprolith]

Each proc (MH/OH innate/aug) can be considered to have a rate that's independent of the others. So you can't calculate an error over the total ppm, you have to add up the individual errors harmonically. You still have the freedom of choosing the confidence interval of course, personally i always use the 95% interval (2*standard deviation) as the standard error.

Here's how i calculate the errors
E.g.
WA0, MH innate proc:
631m, 1.967ppm
# procs=1241
#combat rounds = 60*631/(1.9/1.41) = 26692
%proc/round = 4.65%
statistical error (95% confidence interval) = 2*sqrt(0.0465*(1-0.0465)/26692)) = 0.26%
statistical error in ppm = (0.26/4.65)*1.967 = 0.11 ppm

You can do the same for the other 3 procs then add the 4 errors according to
total error = sqrt(err1^2 + err2^2 + err3^2 + err4^2)
and then you'll get 5.695+/-0.187, or 3.3%

Like I've stated in the past, if you don't like the data, you can always do it yourself.

I love the data and i love people that take the time to parse things properly. No one could be expected to parse this particular skill for months instead of nights. But the sad truth is that because the proc rates are so low you'll have to deal with a sizeable error even when you parse overnight, its just unavoidable within any reasonable amount of time. On the plus side, that also means your data is not in contradiction with the +10% per WA-level rule, which was the question that triggered this discussion. And if there's no reason to assume that its more complicated then that simple rule then i don't  :wink:

/hugs