A PRELIMINARY STUDY OF PUBLIC UNDERSTANDING OF GEOLOGIC TIME PRINCIPLES CONDUCTED AT THE TRAIL OF TIME INTERPRETATIVE EXHIBIT IN GRAND CANYON NATIONAL PARK

The spectacular geological panoramas of Grand Canyon National Park motivate the curiosity of visitors about geology. However, there is little research on how well these visitors understand the basic geologic principles of relative geologic time, superposition, and lateral continuity of strata. The new Trail of Time interpretative exhibit along the South Rim uses Grand Canyon vistas to teach these principles. The 2-km Trail, permanently marked at intervals of 1 meter (each representing 1 million years) and incorporating numerous displays, is the world's longest timeline exhibit. Now being visited by thousands daily, the Trail of Time is a uniquely valuable setting for research on informal learning of geologic time and other basic geological concepts. At the Trail of Time, visitors are not only asked to comprehend a linear timeline, but to associate it with the vertical strata in the walls of the Canyon. Our mixed-methods research addressed two primary questions: (1) Do visitors successfully reconcile the vertical representation of time in Grand Canyon strata with the horizontal timeline presented in the Trail of Time? and (2) How well do Grand Canyon visitors understand the geologic principles of geologic time, superposition, and lateral continuity?

Semi-structured interviews were conducted along the Trail of Time during summer and fall 2009. Interview questions tracked participants' understanding of the Trail of Time exhibit and of basic principles of geologic time. Preliminary quantitative data indicate that not only do a majority of respondents comprehend the horizontal timeline, but they correctly reconcile the vertical and horizontal encoding of time. Initial results also indicate that a majority of respondents understood and could explain the principles of superposition and lateral continuity. Further quantitative and qualitative analysis of interview results will identify the most difficult concepts, to inform future design of outdoor timeline exhibits.