BAND_K (1.28) is the half-width of the IBM replicate band in standard
deviations. Plus or minus 1.28 standard deviations is the 10-90% interval of
a normal distribution, so the band estimates the interval the claims name
from every replicate rather than from two order statistics. Measured over the
91 tier-2 cells, the percentile band moves more under a jackknife (0.074
against 0.072 standard deviations) and is about 10% narrower than the
interval it estimates, because sample percentiles from twenty points are
biased inward. Its width also drifts with the replicate count (2.06, 2.24 and
2.32 at n = 8, 14 and 20) where this band holds at 2.49, 2.54 and 2.56.
Details
BURDEN_MIN (0.05) is the share of an outcome a cell must carry to be
tested by a claim about how that outcome is distributed. Cells carrying
almost none of it say little about the distribution and carry the most
replicate noise. At 5% the tested cells still hold 94% of episodes; the cost,
recorded against the claims that use it, is that a defect confined to the
oldest ages would not be caught.