There appears to be a growing agreement among the users of geographic and land information systems that common sets of geographic data on which users could build to their own particular data needs would promote greater data sharing among the various players in the geographic information system (GIS) community (NRC 1994). Such common data sets, referred to as "core" or "framework" data sets, could be collected by designated government agencies or by participating members of the private sector and added to the public domain, via the National Spatial Data Infrastructure (NSDI), for the use of any and all interested parties. There are many existing digital geographic data sets that enjoy great popularity among various members of the GIS community. However, there appears to be no clear consensus of which geographic data sets would be of greatest value to these government agencies and private businesses. This report is concerned with the identification and prioritization of framework data sets. To help discover which framework data sets should be given priority for incorporation into the NSDI, the Federal Geographic Data Committee (FGDC) has funded a mail questionnaire survey that was conducted by the National Center for Geographic Information and Analysis (NCGIA) with oversight by a peer focus group.