IN THE film "The Devil Wears Prada", the character of Miranda Priestly, whose role is based on a feared Vogue editor, scolds her new assistant for not understanding fashion. Fashion, she tells her, is whatever a select group of designers and critics says it is. What she does not say, however, is that their judgments are themselves often influenced by another group: fashion forecasters, who predict what will be "in". Might these seers of style in turn be undone by artificial intelligence (AI)? Fashion forecasting has always been a peculiar profession. The business came into its own in Paris in the 1960s when agencies began releasing "trend books", collections of fabrics and design ideas.