Tuesday, May 12, 2015

At The Skeptical Zone: A question for Winston Ewert

I’ve invited Winston Ewert to join a technical discussion at The Skeptical Zone. I do solemnly vow to keep it perfectly civil. It would be better to comment there than here. But suit yourself.

I actually have three technical questions for Winston, but plan on one post apiece. He should respond first to questions he receives through Google Moderator, including those from DiEb, who has added a relevant post to his blog. Hopefully he will join us here when he’s done with that.

Let’s be clear from the outset that off-topic remarks go straight to Guano. (If you attack Winston personally while I am trying to draw him into a discussion of theory, then I will take it personally.) You shouldn’t make claims unless you have read, and believe that you mostly understand, the material in all three sources in note 3, apart from the proofs of theorems. Genuine requests for explanation are, of course, welcome. They’re especially welcome if you’ve made a genuine effort to get what you can from the sources.

The overall thrust of my questions should be clear enough to Winston, though it won’t be to most readers. I’m definitely not laying a trap for him. The first two questions have answers that are provably right or wrong. The third is more a matter of scientific modeling than of math. I’m starting with it because TSZ isn’t yet configured to handle embedded LaTeX (mathematical expressions).


1. What is the formal relationship between active information and specified complexity?

2. What is the formal relationship between active information and average active information per query? Does the conservation-of-information theorem apply to the latter?

3. Your search process decides when to stop and produce an outcome in the search space. A model may do this, but biological evolution does not. How do you measure active information on the biological process itself? Do you not reify a model?


1. There’s an answer that covers both Dembski's 2005 version (the probabilistic complexity minus the descriptive complexity of the target) and the algorithmic version of specified complexity. For the latter, it’s apparently necessary to restrict the target (no longer called a target) to a single-element set.

2. The conservation-of-information theorem applies to active information. Winston and his colleagues have measured only average active information per query (several closely related forms, actually), which seems unrelated to active information, in their analyses of computational evolution and metabiology. Yet they refer to conservation of information in exposition of those analyses.

3. The search process of Dembski, Ewert, and Marks terminates, and generates an outcome. The terminator and the discrim­inator of the search in fact contribute to its active information — bias, relative to a baseline distribution on outcomes, in favor of a target event. However, biological evolu­tion has not come to a grinding halt, and has not announced, for instance, Here it is — birds! It seems that Winston, in his ENV response to a Panda’s Thumb post by Joe Felsenstein and me, tacitly assumes that a biologist has provided a model that he can analyze as a search, and imputes to nature itself the bias that he would measure on the model of nature. If so, then he erroneously treats an abstraction as though it were something real. Famously, The map is not the territory. Perhaps Winston can provide a good argument that he hasn’t lapsed into reification.

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