In Asa H 2.0 light I typically use pattern length and frequency of pattern occurrence as components of a case's vector value/utility. (see my blog of 19 Feb. 2011) A pattern's complexity can also be used in measuring its importance. It is not clear which measure of complexity to use, however, permutation entropy? (Brandt and Pompe, Phys. Rev. Lett., 11 April 2002) Ke and Tong's measure? (Phys. Rev. E, 2008) or what?