1. A method of generating an ordered sequence of items from a collection of items, at least one of said items of said collection having at least two annotations, the method comprising the steps of: selecting one or more of said annotations; forming a first plurality of groups of items from said collection of items, each item in a group having one or more of said selected annotations in common; selecting a second plurality of said groups of items to form a sequence of groups, each group in said sequence comprising an item having at least one annotation in common with an item of at least one adjacent group of said sequence; and ordering the items within each of said selected groups of said sequence based on said selected annotations.