---- Google Updates and SERP Changes - February 2013
Wilburforce - 5:55 pm on Feb 27, 2013 (gmt 0)
at least a multiple of a standard deviation
could mean 1.1 x SD, or most of the data.
it could not realistically mean >3 x SD (or effectively all the data).
However, if most pages on widget tinkering have the phrase once or twice, a comprehensively informative page (widget tinkering history, widget tinkering in early belgian convents, modern widget tinkering methods...) would almost inevitably fall foul of it.