Summary: UX constitutes many different specialties such as researcher, interaction designer, visual designer, copywriter, and information architect. Forcing one person to do it all is a prescription for mediocrity.
Jakob Nielsen, Ph.D., is a retired principal and co-founder (with Dr. Donald A. Norman) of the Nielsen Norman Group. Jakob established the "discount usability engineering" movement for fast and cheap improvements of user interfaces and invented the heuristic evaluation method.