Comment 13 for bug 571796

So I finally have an answer to a long standing question!
Thank you; Nasenbaer! It's a good thing, you found some time to appear here :)

You are probably right at the mark with your analysis of
the strange jumps in productivity for some buildings.
I guess there may really be some mixups in the sequence of
checks, sleep- and working cycles for some houses.
I have read it again but here is a part I don't understand:

(in the paragraph explaining the coniditions of the +/- signs)
...if the sum is bigger than the complete statistic...
Could you be so kind and clarify this a bit more?