Explanatory Filter

The Explanatory Filter is a method devised by William Dembski for detecting design. In other words a method to detect whether or not any entity was designed by an intelligent agency. The method takes the form of a three-stage Explanatory Filter.

The filter
Putting in simple terms, the filter asks three questions and in the following order:


 * 1) Does a law explain it?
 * 2) Does chance explain it?
 * 3) Does design explain it?

In the book Signs of Intelligence, Dembski ilustrates the explanatory filter. The first diamond ask if there is contingency. If the answer is no, then one can conclude necessity. In his other book, The Design Inference, Dembski uses here a different question: is the event highly probable? if the answer is yes then one can conclude regularity. The second diamond ask if there is complexity. Again, in The Design Inference, Dembski ask if there is events of intermediate probability. In both cases one can conclude chance. The last diamond ask if there is specification. If the answer is no then one can conclude chance, otherwise we conclude design. Once more in The Design Inference, Dembski uses a slightly different formulation asking if the event is an specified event of small probability in which case, if the answer is yes, we can conclude design.