Two Map Critiques

Example of Good Design:

This map succinctly depicts the status of the opposing alliances of the Cold War - NATO and the Warsaw Pact - as they were comprised in 1970. The design minimizes clutter, placing the rest of the world in the background (or simply not depicting it due to the use of an orthographic projection). The map layout, with the North Pole tilted toward the viewer, helps emphasize the proximity of the rival powers.

Map source: From Nuclear Weapons and NATO: Analytical Survey of Literature by United States Department of the Army, 1970. 

From the Perry-Castañeda Library Map Collection, University of Texas

Example of Poor Design:

At first glance, this map is rather striking. It purports to show growth trends among the world’s “Mega-Cities”, which it defines as those with a population of 10 million or greater. However, on closer inspection, the data displayed on the map suffers from being incomplete and incoherent. The megacities displayed on the map have a graphic representation of their populations from 1950, 2000 (an estimate) and 2015 (a projection). One can infer that Mega-City status is conferred based on city populations in 2000, as many of the cities listed had populations much lower than 10 million in 1950. However, this is never defined. However, if that inference is intentional, then this map is woefully incomplete. Several cities that qualified for “Mega-City” status in 2000 are not included on this map. These include Seoul, Delhi, Baghdad, Teheran, Istanbul, Manila and Moscow. Meanwhile, the time increments selected for the population growth graphics for the cities included are inconsistent, spanning fifty years and then just fifteen. The fifty-year span from 1950 to 2000 is also used to depict national population growth trends with a single metric depicted chloroplethically. The metric used is (presumably) on the population difference for each nation from 2000 to 1950. Since each nation had a different starting population, population density and land area, this metric is meaningless. The fifty year timespan is simply too great to show any meaningful trends, anyway, even if the mapmaker had used a per capita growth rate or something else more appropriate.

Map source: From Global Trends 2015: A Dialogue About the Future With Nongovernment Experts [page 29], National Intelligence Council, 2000 

From the Perry-Castañeda Library Map Collection, University of Texas