At first glance the problem might seem far removed from the design detecting rules William Dembski laid out in his Cambridge University Press monograph.
Dembski says he stands by that work and his early contributions to intelligent design theory, but adds that he has learned a lot more in the intervening years.
Not all patterns eliminate chance in the presence of improbability. Take an arrow shot at a target.
Briefly, the design inference (the method rather than the book) identifies two features as essential for eliminating chance: improbability and specification.
Rational agents often detect the prior activity of other designing minds by the character of the effects they leave behind.