This volume contains the papers presented at the Conference on Spatial Inf- mationTheory, heldinEllicottville, NewYorkinSeptember 2005.COSIT2005 was the 7th International Conference held under the COSIT name. When - drewFrankandhiscolleaguesorganizedthe?rstCOSITconferenceontheisland of Elba, Italy, in 1993, it represented the maturing of an international research community that had already met four or ?ve times in the United States, Spain, and Italy. Of course, cognitive and computational approaches to space and s- tial phenomena werenot themselves new topics, but a contextof providingth- retical underpinning for geographicinformation systems refocused some of these researchers and brought them up against practical and conceptual challenges. A second international symposium under the COSIT name, held in Semmering, Austria in 1995, established COSIT as a biennial conference series that cont- ued at Laurel Highlands, Pennsylvania, USA (1997), Stade, Germany (1999), Morro Bay, California, USA (2001) and Ittingen, Switzerland (2003). A prod- tive partnership with Springer s Lecture Notes in Computer Science has ensured that the papers from every COSIT meeting have been widely disseminated, and the COSIT community has contributed signi?cantly to the development of G- graphic Information Science, Geoinformatics and Spatial Information Theory in general."