Communicating Through Maps in a Modern GIS World

Maps remain one of the most enduring and powerful tools for representing information. For readers immersed in geospatial technologies, their value may seem self-evident. Maps reveal spatial distributions, illuminate patterns, and provide a framework for analysis and communication. They are both analytical instruments and expressive media—tools for discovering meaning and conveying it.

The metaphor of a “map” extends beyond geography because organizing information spatially—whether words, numbers, images, or concepts—helps us interpret relationships. Geographic Information Systems (GIS) were developed to manage and analyze spatial data, but printed maps are only one of many possible outputs. In fact, once a digital map is printed, it becomes disconnected from its dynamic, database-driven origins. The static product severs the link to the data that sustains it.

In disciplines historically rooted in printed cartography, such as geology, professionals increasingly advocate for digital alternatives that enable sharing, interaction, and continuous updating. As interoperability improves and web mapping expands, the proportion of projects culminating in paper maps will likely decline. Yet regardless of medium—print, PDF, web, or interactive dashboard—maps remain central to decision-making, explanation, and spatial reasoning.

This article launches a series examining how maps communicate. Subsequent contributions will explore topics such as uncertainty representation and best practices in web-based cartography. Here, we begin with foundational considerations.

First Impressions and Cognitive Processing

The communicative strength of a map depends heavily on cartographic design. Yet formal cartography training is uncommon, even within many GIS degree programs. While organizations such as Carto, Stamen, Esri, and others embed thoughtful design principles into their platforms, responsibility ultimately rests with the mapmaker.

The moment someone views a map, complex cognitive processes begin. Human perception seeks structure, separating figure from ground, identifying patterns, and interpreting shapes according to principles such as those described in Gestalt psychology. Visual perception is not neutral—color blindness affects differentiation, and prior experience shapes interpretation.

Every viewer approaches a map with a unique combination of background knowledge and expectations. Some may understand the geographic context intimately; others may lack even basic familiarity with map-reading conventions. Designing effectively for both novices and experts presents a persistent challenge.

The reality is that layout design is often the final stage of a GIS workflow—and frequently rushed. Investing time in iterative drafts and resisting reliance on default symbology can dramatically improve clarity. For many viewers, the first exposure to a map may also be the last. A poorly considered design can undermine the intended message before it is fully processed.

Trust, Authority, and the Illusion of Objectivity

Maps carry an authority that photographs and other graphics often do not. While manipulated images have made audiences wary—“photoshopped” has entered common vocabulary—maps tend to be accepted without similar skepticism. Despite the fact that cartographic manipulation has long served political, military, advertising, and privacy agendas, most viewers rarely question a map’s assumptions or construction.

Early exposure to authoritative government maps—such as those from the U.S. Geological Survey—instills confidence in standardized symbols and clean linework. As a result, even contemporary web maps benefit from inherited credibility. This trust persists despite the relative ease with which digital geospatial data can be modified, filtered, or symbolized to emphasize certain narratives.

Legends are intended to decode a map’s symbols, yet many viewers skim or ignore them. In high-pressure contexts, such as emergency response, there may be little time for careful legend review. Even in calmer settings, short attention spans and aversion to instructions reduce scrutiny.

Introductory GIS courses often demonstrate how classification schemes in choropleth maps alter visual impressions. Changing bin thresholds can dramatically shift which areas appear “high” or “low.” Yet most map users have never encountered such exercises. They absorb overall impressions—dark versus light regions—without examining classification breakpoints or methodological notes.

This dynamic is particularly concerning when maps inform consequential decisions. The persuasive power of a map may exceed the viewer’s capacity to critique it.

The Visual, Spatial, and Geospatial Dimensions

Maps function at the intersection of visual and spatial cognition. The label “visual learner” is often used to describe preference for graphics over text, but in reality nearly all sighted individuals rely heavily on visual information. The phrase “a picture is worth a thousand words” reflects not just preference but efficiency—the speed at which meaning can be extracted from imagery.

Map interpretation, however, extends beyond visual decoding. It requires spatial reasoning—understanding proximity, distance, scale, and overlay. Observing whether features cluster, disperse, or align along gradients prompts inferences about underlying processes. GIS tools formalize these spatial concepts into analytical operations.

Scale further complicates interpretation. Digital mapping environments allow users to zoom freely, sometimes beyond appropriate levels of detail. Without attention to scale dependencies, users may misinterpret generalized or incomplete information.

Temporal communication adds yet another layer. Animation and interactive time sliders can illuminate change over time but may also overwhelm or distract if poorly designed. Communicating temporal dynamics demands thoughtful design choices—an issue that will be explored later in this series.

GIS-based mapping also reveals phenomena invisible to direct observation: hazard probability surfaces, groundwater contamination plumes, or modeled viewsheds from historical vantage points. In such cases, maps act as proxies for realities that cannot be directly experienced. They are abstractions, yet they remain uniquely capable of synthesizing complex geospatial relationships.

The Synergy of Map Communication

Effective maps blend visual design, spatial reasoning, and geospatial analysis into a cohesive communicative experience. When executed well, the result resembles a harmonious convergence—much like balanced acoustics in a well-designed space or the layered richness of flavor in cuisine. Each element enhances the others.

As this series continues, we will examine more specific aspects of communicating through maps. For now, three foundational principles emerge:

• Thoughtful design and iterative refinement are essential; first impressions matter deeply.
• Maps carry implicit authority, yet viewers rarely interrogate their construction.
• The combination of visual, spatial, and geospatial information creates a uniquely powerful communicative medium.

In a world increasingly saturated with digital information, the map remains one of the most influential ways to structure, analyze, and convey meaning.