"Before a map can be drawn, a cartographer has to consider constraints that will influence its design. These include the purpose of the map, user characteristics, the use environment, and data characteristics. The purpose of a map, which can be manifold, relates to the questions the map will have to answer, or it use requirements. […] Above all, however, data characteristics will influence a mapmaker’s choice of symbology, because qualitative and quantitative data cannot be expressed in the same way." (Menno-Jan Kraak, "Mapping Time: Illustrated by Minard’s map of Napoleon’s Russian Campaign of 1812", 2014)
"Designs that play the role of presentation usually inform about spatial patterns and relations. This reflects the traditional cartographic approach. The cartographer begins with a known set of data and must select an appropriate visualization technique that will produce a high-quality explanation of facts. In other words, the visualization process ends with the best possible map. Map design, then, is important." (Menno-Jan Kraak, "Mapping Time: Illustrated by Minard’s map of Napoleon’s Russian Campaign of 1812", 2014)
"Graphic representations such as maps and diagrams should be able to answer all kinds of spatiotemporal questions, whatever the given situation. Not all graphics are suitable; even if they are, the data behind the graphics should be archived in a well-organized database." (Menno-Jan Kraak, "Mapping Time: Illustrated by Minard’s map of Napoleon’s Russian Campaign of 1812", 2014)
"In contrast to flow maps, origin-destination maps’ paths are highly structured, and do not use arrowheads to indicate direction. Both types of maps illustrate the volume of flow by varying the thickness of the path line’s shaft, some by gradually trimming the thickness of the shaft, others by splitting the shaft into sections and giving each section its own uniform thickness." (Menno-Jan Kraak, "Mapping Time: Illustrated by Minard’s map of Napoleon’s Russian Campaign of 1812", 2014)
"[…] information is lost or gained during the communication process.
Information could be lost whenever a cartographer chooses to suppress
information and/or users fail to understand all of it. It can be gained
whenever the cartographer clarifies the original set of data and/or users
combine the map information with their prior knowledge."
"One cannot always be fully acquainted with the data, however. In such cases, exploration helps to judge the data’s usefulness. The exploration process, which emphasizes discovery, often facilitates an interactive, undirected search for structures and trends. This may result in conclusions that lead to alternative hypotheses." (Menno-Jan Kraak, "Mapping Time: Illustrated by Minard’s map of Napoleon’s Russian Campaign of 1812", 2014)
"We use maps to help us understand the world around us in the most effective and efficient way. Maps can summarize, clarify, explain, and emphasize aspects of our environment. Maps can play many roles. They support navigation and decision making, they of f er insight into spatial patterns and relationships among mapped phenomena, and […] they can tell stories. Maps do this well because they symbolize and abstract the reality they represent." (Menno-Jan Kraak, "Mapping Time: Illustrated by Minard’s map of Napoleon’s Russian Campaign of 1812", 2014)
