Tom English has a great post at his blog, Bounded Science, which I have his permission to cross post here:
Bob Marks grossly misunderstands “no free lunch”
And so does Bill Dembski. But it is Marks who, in a “Darwin or Design?” interview, reveals plainly the fallacy at the core of his and Dembski’s notion of “active information.” (He gets going at 7:50. To select a time, it’s best to put the player in full-screen mode. I’ve corrected slips of the tongue in my transcript.)
[The “no free lunch” theorem of Wolpert and Macready] said that with a lack of any knowledge about anything, that one search was as good as any other search. [14:15]And what Wolpert and Macready said was, my goodness, none of these [“search”] algorithms work as well as [better than] any other one, on the average, if you have no idea what you’re doing. And so the question is… and what we’ve done here is, if indeed that is true, and an algorithm works, then that means information has been added to the search. And what we’ve been able to do is take this baseline, that all searches are the same, and we’ve been able to, in cases where searches work, measure the information that is placed into the algorithm in bits. And we have looked at some of the evolutionary algorithms, and we found out that, strikingly, they are not responsible for any creation of information. [14:40]
And according to “no free lunch” theorems, astonishingly, any search, without information about the problem that you’re looking for, will operate at the same level as blind search.” And that’s… It’s a mind-boggling result. [28:10]
Bob has read into the “no free lunch” (NFL) theorem what he believed in the first place, namely that if something works, it must have been designed to do so. Although he gets off to a good start by referring to the subjective state of the practitioner (“with a lack of knowledge,” “if you have no idea what you’re doing”), he errs catastrophically by making a claim about the objective state of affairs (“one search is as good as any other search,” “all searches are the same”).


