🚀 go-pugleaf

> One of our Directors has asked me to inquire about a reputed Bell labs
> study from 7 or so years ago, which he heard about at a conference. This
> study was on "failure probabilities"; one of the statements or
> conclusions he recalls was that if you have a string of five sequential
> decisions, one after the other, each based upon the preceeding, the
> reliability of the result is at the 59% level. I don't really have much
> other than this to go on, so, if this comment rings a bell with you, and
> you know the study (or studies) that this sort of conclusion came out
> of, I would greatly appreciate it if you could mail me a reference. If
> you know of work being done in this area by other organizations or
> particular researchers, any comments or rumors or hearsay or pointers to
> published work or theses would be welcomed.

Gee, this is hardly revolutionary.  If you assume a single decision
can be made with 90% confidence, and successive decisions are
statistically independent (important!), then the confidence for
the composition is (90%)^5 which is about 59%.  This is very
elementary probability theory; almost any mathematically trained
person could reproduce this -- it isn't any research specialty.

Perhaps you are really interested in "fault tree" analysis or
rare-event estimation, such as is used in predicting failure
rates for nuclear reactors and other such systems where empirical
data are few or non-existent.