This report is a summary of the Specialist meeting for NCGIA Research Initiative 7 entitled "Visualization of Spatial Data Quality" . It presents initial discussions on the role and utility of visualization for understanding and analyzing information about the quality of GIS data. The impetus for the initiative is based on rapid changes in spatial information system technology and a desire to see the technology used more effectively. Technology currently allows us to process and display large volumes of information very quickly. Effective use of this information for analysis and decision making presupposes that the information is correct or reasonably reliable. Information on the quality of data is essential for effective use of GIS data: it affects the fitness of use of data for a particular application, the credibility of data representation and interpretation, and the evaluation of decision alternatives. The credibility of spatial decision support using GIS may indeed depend on the incorporation of quality information within the database and the display.