Just listen to some of the comments from the dust jacket of the book from secular philosophers and mathematicians. Not since David Hume's Dialogues Concerning Natural Religion has someone taken such a close look at the design argument. Being put in the same sentence as David Hume is no small potatoes. Dembski has rigorously detailed the key trademark of intelligent causes, what he calls specified complexity. The term specified refers to the notion that an event conforms to an independently given pattern.
Complexity refers to an event of small probability.
For instance, people win improbable lotteries all the time. The odds are usually in the millions to one. But when the number of tickets purchased is considered, nobody questions the legitimacy of someone holding the winning ticket. This would be an event of small probability without any specification. Somebody will win, but nobody can predict whom.