Desert fog

WHAT

The desert fog pattern offers no discernible UI patterns such as search or home button and no orientation clues on the map, leading to a loss of orientation for map users. Without these elements, it is increasingly easy to get lost in multiscale systems.

WHY

The reason users interact with maps is to explore data that is spread across vast extents and multiple scales. As users navigate unfamiliar geographic areas, they can easily lose their sense of place and start feeling trapped. Without additional information or clues that help users recover their sense of identity and get back on track, they will become “lost in the desert fog” — hence the name of the pattern. The same undesired outcome can occur after users choose an interaction by mistake or realize that their action wasn’t what they wanted or needed. To avoid the desert fog problem, builders must consider the usability heuristic “user control and freedom,” which states that great apps need to find the correct balance between enabling users and avoiding unwanted outcomes. The goal is to make people feel that they’re in control and that there is an easy way to recover. This fosters a sense of freedom because users realize they don’t need to be afraid of interacting with the UI.

WHEN

Desert fog can occur frequently when panning or zooming in an area in which there are no features that might help orient the user. Almost every map app must therefore provide one or multiple solutions to prevent the sense of losing orientation.

HOW

Various solutions can be used to avoid the desert fog problem. Some are related to the map and others to the app. The map plays a crucial role in communicating place, so you should consider the following cartography-related solution approaches:

Labels: Make labels clear and legible with high contrast to the basemap
layer. Consider adding a halo that resembles the dominant background
color to ensure readability regardless of the underlying layers.
Key features: Add visually salient or well-known features, such as
landmarks, highways, rivers, or mountains. These features help users
retain orientation during map reading.
Reference layers: Include reference layers such as state or county lines.
Visual cues: Consider adding other visual cues such as grid lines.

Most of the app-related solution approaches use components that are superimposed on the map. The following list describes the patterns that help avoid desert fog through the app:

Home button: Restore initial map extent to a well-known area.
Locate me: Re-center the map to the user’s current location.
Placemarks: Provide shortcuts to important places, such as US territories,
that would require a lot of navigation otherwise.
Overview map: Tell users where they are in relation to a wider view.
Location finder: Search for a place as a final escape hatch.

Finally, avoid ambiguous affordances that would confuse users about the correct use of UI elements. Always use components that are predictable and familiar.

EXAMPLE

The map below shows the third-largest city measured by land area in the state of California. Without additional clues, a user would probably not be able to guess where or what this city is and be lost in the desert fog. The city is California City, incorporated in 1965 and master planned to rival other major cities in California. Located about 100 miles north of Los Angeles in the Mojave Desert, it has a current population of about 15,000.

To better communicate the content of the map, builders could add city labels and other key features such as highway shields. Another method to provide important context and identify the location faster is an overview map. Adding a home button or location finder can be helpful to reset the current map view.