#design detection

The second edition of The Design Inference was recently released. Winston Ewert from the Biologic Institute coauthored the book with William Dembski who wrote the first edition. The original book presented a general methodology for detecting design, which was the most sophisticated framework to date. The second edition represents the culmination of two decades of responding to critics and refining his model. Princeton University mathematician Sergiu Klainerman welcomed the book as follows:

Well argued and eminently readable… I don’t see how any open-minded scientist can ignore this important book.

The first edition of The Design Inference explained how design detection involves identifying patterns that are both highly improbable and specified. A common question raised by readers was the precise definitions for the terms specified and specification. In other words, what exactly makes a pattern specified or special? In many contexts, the answer is simple. For instance, being dealt four poker hands that were all royal flushes would be a very rare and special pattern pointing to someone cheating. Design detection in this example is easy because the category royal flush was already defined (aka prespecified) by the rules of the game. The situation is more challenging when categories of outcomes are not so clearly defined. 

In the new edition, Dembski and Ewert greatly refined the concept of specifications. They defined a specification as a description that requires few words. The description must also only apply to a small proportion of possible outcomes, so the probability of any outcome falling within the specification must be sufficiently small. Patterns that are both identifiable by a short description and highly improbable are almost always designed.  

Returning to the poker example, the four hands I mentioned could be described or specified by the three words four royal flushes, and the probability of four random hands falling within this specification is less than 1 chance in 100 billion trillion. The short description and very low probability indicate design. 

In contrast, four typical hands of five cards would require a very long description, such as the following:

two of diamonds, pair of threes, pair of jacks; three fours, nine of hearts, ten of clubs; four of diamonds, pair of eights, nine of clubs, queen of clubs; three kings, pair of aces

The probability of four hands falling within this description is low, but the description length is very long. Many sets of four poker hands would fall within a description of that length. The low probability is offset by the large number of sets of four hands with descriptions that are that long. The probability of being dealt four hands with such a long description is not sufficiently low to conclude design. 

Conversely, one could label four generic hands with the description random cards. The description is now short, but the probability is very high of four hands falling within this description. The short description is offset by the high probability. Similarly, the famous face on Mars can be described by the two words fuzzy face. Here again, the description length is short, but the probability of a photograph of the surface of a celestial body resembling a face at least as well as the Mars photo is sufficiently high to occur by chance. 

The face on Mars (NASA/JPL)

The underlying logic of Dembski and Ewert’s methodology is profound. Identifying design requires a pattern being assigned by a mind a special significance. A short description meets this criterion since societies assign words or short phrases to that which they designate as special. 

To illustrate, in the movie The Empire Strikes Back, Darth Vader declares to Luke Skywalker one of the most iconic lines in movie history: "I am your father."

Darth Vader could specify himself by the single word father. The relationship between a father and son is designated by all societies as a very special relationship. Relatively few other people could be specified by such a short description. Consequently, the audience knew Luke’s meeting Vader was not an accident but by design. 

In stark contrast, Dark Helmet in the movie Spaceballs tells Lonestar a far longer statement: "I am your father’s brother’s nephew’s cousin’s former roommate."