There are many examples of this problem. SIDS [1] is similar: there's no way for experimenting, it's extremely difficult to find out the circumstances when some

There are many examples of this problem. SIDS [1] is similar: there's no way for experimenting, it's extremely difficult to find out the circumstances when something bad happens; and if you can somehow record them, then it's extremely difficult to find out what's relevant and what's not. [1] http://en.wikipedia.org/wiki/Sudden_infant_death_syndrome http://en.wikipedia.org/wiki/Sudden_infant_death_syndrome