The steering committee meets on a monthly basis and serves as the senior management team of the Intellectual and Developmental Disabilities Research Center (IDDRC). The steering committee is comprised of core directors, associate directors and the IDDRC administrator. The Administrative Core is responsible for the establishment and maintenance of the ad hoc advisory committees of the IDDRC. The internal and external advisory committees serve as the board of directors for the IDDRC. Instead of meeting annually as a group, members of the external advisory committee are invited individually as visiting professors to lecture and to provide informal consultation and formal review of the individual cores. The internal advisory committee is equally talented, consisting of a number of department chairmen at the University of Pennsylvania who have an interest in research at the IDDRC.