A key issue in Chaco archaeology is the large number of Great House communities located outside Chaco Canyon—sites often referred to as “outliers.” The geographic distribution of those sites (fig- ure 5.1) delineates the “Chaco World,” although the actual nature and dynamics of that world are matters for research, not assertion. For example, the commonly used term outlier has implications for the his- tory of Chaco Canyon that may or may not be warranted (see Mills 2002 for an excellent overview of Chaco studies and recent studies on this theme). This chapter summarizes research on questions generated in the Chaco World conference and the Chaco Synthesis: How do we define Chacoan or Great House communities? What level of interac- tion occurred among these communities and between Chaco Canyon and them? What degree of symbolic and sociopolitical unity existed across the Chaco world? 1 At the end of this chapter, we assess the Chaco Timeline from the perspective of research outside Chaco Canyon. G R E AT HOUSE COMMUNITIES What was the Chaco world? Kintigh (2003) reviews the substantial confusion and disagreement that surrounds research on Chaco. Not 1 5 3 5 The Chaco World John Kantner and Keith Kintigh Arch Chac 05 10/4/05 11:15 AM Page 153