According to
Douglas Hoffstader's book,
Gödel, Escher, Bach: An Eternal
Golden Braid, i-mode is one of the
three modes of
human action ( the other
two being
m-mode and
u-mode ).
A person is working in "intelligent mode"
when actions are based on observation, deduction, logic, and any other
intellectual abstraction.
For example, that act of trying to determine someone's E2 password by
looking at their homenode and attempting to guess what they might use is
acting in intelligent mode.