19. The computer program product of claim 15 wherein the story angle data of the angle set data structure further comprises, for each story angle, data representative of an importance value for that story angle.
15. The computer program product of claim 3 wherein the angle set data structure further comprises data for a plurality of story angles, the story angle data comprising, for each story angle (1) an identifier for that story angle, and (2) data representative of at least one applicability condition for that story angle.