Visualizing Metadata: Design Principles for Thematic Maps

Abstract

This paper argues that the best way to transmit metadata to thematic map users is through cartography rather than text notes or digital means. Indicators such as reliability diagrams, common on maps derived from air photos or satellite images, are rarely included on thematic maps based on the census or other socioeconomic data sources. These data not only suffer from an array of quality problems but also are widely distributed among the general public in cartographic format. Metadata diagrams for thematic maps based on human variables therefore must be clear and concise, so as to be comprehensible by the non-specialist. Principles of good metadata diagram creation are proposed, with attention to the balance between clarity and space constraints.