7 Degrees of Penetration? (was Re: The Devil's Dictionary and repetition)

[davemarc]

Ken Smith, author of Mental Hygiene (a book about American educational
films), has been making presentations this month at the American Museum of
the Moving Image in Astoria, Queens.

Last weekend, he spoke about a 7-second rule or standard that dictated that
in educational films (and presumably other educational media) a point must
be made for seven seconds for it to have an adequate impact on students.

d.