Asahi, ToshiyukiTuro, D.Shneiderman, B.Treemaps, a visualization method for large hierarchical data spaces, are used to augment the capabilities of the Analytic Hierarchy Process (AHP) for decision-making. Two direct manipulation tools, presented metamorphically as a "pump" and a "hook", were developed and applied to the treemap to support AHP sensitivity analysis. A usability study was conducted using a prototype AHP application; results showed that treemap representation of decision-support tools was acceptable for AHP users from both a visualization and data operation standpoint. Subjective preferences were high for AHP treemaps.en-USvisualizationtreemapanalytic hierarchy processAHP decision supportSystems IntegrationTechnical Report