A Map User Study Conducted at Zion National Park, United States

Th is paper discusses the fi ndings of a comparative user study conducted in Zion National Park, Utah, in September 2006, which tested conventional (2D) and perspective (3D) trail maps in an outdoor setting. Th e study aimed to answer questions about the eff ectiveness of both map types for communicating cartographic information, whether hikers are attracted to one map type over the other, and the map preferences of hikers at Zion National Park. Th e fi ndings revealed that 2D and 3D maps have diff erent strengths and weaknesses for communicating trail information to park visitors. Th e decision about which map type to use should be made on a case-by-case basis, depending on the steepness of the terrain through which the trail passes, and the hiking experience and demographic characteristics of typical users of the trail. Introduction 1. Many inexperienced map users have trouble reading 2D topographic maps that typically depict landscape features with contour lines, shaded relief, and height points. To help these users, which comprise a large segment of the general population, cartographers have increasingly turned to 3D perspective maps, which allow users to more easily visualize three-dimensional landscapes. Applications such as Google Earth and the Atlas of Switzerland indicate the growing popularity of 3D maps in recent years. However, as useful as 3D maps are, they are not without problems: compared to 2D maps, they are more time-consuming and expensive to produce; scale diminishes from the front to the back of the map, making distances diffi cult to judge; and high mountains can obscure adjacent lowland areas and slopes facing away from the reader, depriving the reader of critical information. Little research presently exists on the eff ectiveness of 3D maps in general, and less information is available about their eff ectiveness for hiking, the focus of this study. Most research on the topic relies on surveys of expert users (Häberling, 2003; Petrovič and Mašera, 2006) or students. Small sample sizes and testing conducted in controlled indoor settings are the norm. Th e research presented here, in contrast, evaluates 2D and 3D maps by gathering data from a large sample of actual hikers at Zion National Park, Utah. Th e study investigated the trailhead maps that hikers see before setting off on a hike. Th e idea for the study originated at International Cartographic Association (ICA), Commission on Mountain Cartography (CMC) workshop at Vall de Núria, Spain in 2004. At that meeting, US National Park Service (NPS) cartographer, Tom Patterson, questioned whether the 3D maps increasingly used by the NPS for trailhead exhibits were worth the extra time and expense to produce—about twice the cost of 2D maps. Patterson presented an outline for a proposed study to investigate the eff ectiveness of 3D trailhead maps compared to 2D maps. David Schobesberger, then a graduate student at the Institute of Geography and Regional Research, University of Vienna, teamed up with Patterson and expanded and refi ned the study for his M.A. degree research. Schobesberger was the principal investigator for the study, which took place in September 2006 at Zion National Park. Defi nition of 2D maps and 3D maps 2. Th is article uses the terms 2D maps or conventional maps for maps that depict the surface of Earth from a theoretical vantage point of directly overhead, in an orthogonal projection. Two-dimensional maps have relatively equal scale in the x and y dimensions. From topographic sheets to atlas plates to road maps, the vast majority of maps available today are of the 2D variety. By comparison, 3D or perspective maps, often called birdseye views or panoramas, depict the terrain with faux threedimensionality and contain perspective that diminishes the scale of distant (background) areas. Häberling (2005) defi nes a 3D map as a “computer-generated perspective view of a three-dimensional geo-data model with cartographic content.” German-language cartographic literature usually refers to 3D maps not as maps, but rather as map-related representations (Hake, 2002). Th ree-dimensional maps are suitable for display on printed brochures, computer monitors, outdoor exhibit panels, and a variety of other twoEvaluating the Eff ectiveness of 2D vs. 3D Trailhead Maps 202 • Mountain Mapping and Visualisation 6th ICA Mountain Cartography Workshop dimensional media surfaces. Fig. 1 shows the 2D and 3D maps used for comparative evaluation for one of two trails studied at Zion National Park. Th e following summarizes the assumed advantages and disadvantages of 3D maps. Advantages of 3D maps: Th ey appeal to readers, especially in informal situations such as when on holiday. For example, the eye-catching 3D maps often used in ski resort advertisements. Th e virtual camera position and viewing direction are customizable. Readers can easily visualize and understand elevation diff erences and topographic features. Overlaying thematic or photo-realistic information is possible. Disadvantages of 3D maps: Scale varies from front to back within a scene. High topographic features can obscure information in the background. Printing of vector lines on 3D terrain is diffi cult. 3D map production requires more time than for 2D maps. 3D maps are more expensive to make than 2D maps. Successful production depends on a high-quality digital elevation model, which is not always available. Specialized software is needed for production. Standardized techniques for 3D map production are not familiar to many cartographers. Research goals and study design 3. Th e goals of the study were to fi nd out the diff erences in communication effi ciency between 2D and 3D maps, which type of map attracted the attention of more people and motivated them to go hiking, and the type of map preferred by park visitors. Th e study used two methods for collecting data. Trailhead monitoring: involved mounting either 2D or 3D maps at the trailhead exhibits on alternating days, and monitoring the exhibits from far enough away so as not infl uence the park visitors’ behavior and interaction with the map. Th e principal investigator noted hiker characteristics and the time that they spent interacting with the maps. Questionnaires: the principal investigator conducted hiker interviews at midway point along the studied trails, noting the respondents’ answers on standardized forms. Th e questionnaire had four parts: Th e 2D map (left) and 3D map (right) of the Emerald Pools trails used for comparative testing. Fig. 1: 2D and 3D trailhead maps with equivalent content Fig. 2: and design were displayed for testing on alternating days and under similar conditions. Source: Patterson, 2004.