[jessaustin]

Yes in this instance false negatives are very bad. It's better to reject ten perfectly acceptable roommates than to accept one crazy ax-murderer roommate.

[mrunkel]

not for those ten potential roommates it's not. :)

Is it really rational to reject those 10 roommates for no good reason to avoid the 1 in a million hellish roommates?

[dmurray]

You'd have to reject 9 of them anyway, assuming you only have one room to let. It's not a big deal to reject all 10.

[snvzz]

>not for those ten potential roommates it's not. :)

But you're doing what makes sense for yourself. Why would you consider a random stranger above yourself in such a situation?