Cleaning up for the Housekeeper: or Why it Makes Sense to do both Expert Review and Usability Testing
http://www.usabilityprofessionals.org/upa_publications/upa_voice/volumes/2004/nov/cleaning_up.html
  peer-reviewed

Straub, Kathleen
Usability Professionals Association
2004

Abstract:

Once in a while a client will tilt their head and look at me with one of those smiles. “You want to do expert review and then also usability testing?” they say. “Is this one of those consulting tricks? Why would I need to do both?” It’s a fair question. To the casual observer, usability testing and expert review probably look very similar.