EDITORIAL Editorial I t is a great pleasure and a great honor for me to introduce this new issue of SIGEVOlution that hosts an interview with Stewart W. Wilson. To me, Stewart is a mentor and a great friend. To our community, he is the person who, with XCS and XCSF, singlehandedly revolutionized learning classifier system research. In 1994, his paper on XCS in the Evolutionary Computation Journ...