Using Google Earth to Teach Plate Tectonics and Science Explanations
Blank, Lisa M., Plautz, Mike, Almquist, Heather, Crews, Jeff, Estrada, Jen, Science Scope
In a manner which matches the fortuity, if not the consequence, of Archimedes' bath and Newton's apple, the [3.6-million-year-old] fossil footprints were eventually noticed one evening in September 1976 by the paleontologist Andrew Hill, who fell while avoiding a ball of elephant dung hurled at him by the ecologist David Western.
--John Reader, Missing Links: In Search of Human Origins
While it is true that new ideas in science can and do occur from such creative acts of folly, A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas emphasizes that the practice of science is inherently a model-building activity focused on constructing explanations using evidence and reasoning (NRC 2012). Because building and refining is an iterative process, middle school students may view this practice as tedious and fail to appreciate science as a creative endeavor.
Digital tools such as Google Earth (GE) can help with this challenge, but many classroom applications of GE limit students to passive observation of predeveloped GE tours. We wondered how we could get our students to use GE as a scientist would--to view, explore, and create geospatial visualizations that advance scientific understanding. Consequently, we developed the Cyber-Enabled Earth Exploration Curriculum ([CE.sup.3]). Using [CE.sup.3], students progress from making simple observations in the GE environment to creating their own data files and overlays to evaluate and visualize data (Figure 1).
Does the Earth's structure affect you?
During this four-week unit, our seventh-grade students explored the essential science question "Does the Earth's structure affect you?" We chose this question because it makes science relevant to students' lives, is a core idea in the K-12 framework (Plate Tectonics and Large-Scale System Interactions), and is listed in the framework as a grade 8 endpoint: "Plate tectonics is the unifying theory that explains the past and current movements of the rocks at Earth's surface ..." (NRC 2012, p. 7-9).
In contrast to most curricula addressing this content area, students began by exploring volcanoes and ended with plate tectonics (Figure 2). This sequence was a deliberate attempt to help our students experience the process of discovery that the scientific and lay communities have undertaken through the ages.
Just as scientists do, students were required to maintain a record of their GE observations, measurements, and calculations using a field notebook. When collecting data, students assumed the role of a practicing scientist to help link their field-notebook work with a science career. To encourage students to see their field notebooks as an essential tool for understanding, we asked them to refer to their findings during class discussions. We scaffolded the field notebook so that in the first three investigations, students were prompted, while working in GE, by a field-notebook symbol to indicate important data-collection points. We also provided tables in which to record the data. These supports faded across the investigations so that in the final investigation students decided what to record and how to record the data.
The K-12 framework identifies constructing science explanations as one of the central scientific practices of the K-12 science curriculum. We found the Claims, Evidence, and Reasoning (CER) strategy to be a helpful model for meeting this endpoint (McNeill et al. 2006). For example (Figure 3), after students flew in GE along the mid-Atlantic ridge (identified only as a geographic feature in GE), they were asked to decide if this "scar" was a ridge or a trench (claim), use their data to support their claim (evidence), and justify how these elevation data supported their claim (reasoning).
We observed that it takes significant time to develop students' science explanation skills. Initially, we modeled each step of the CER process, constructed science explanations as a class, and weekly assessed students' science arguments as a class. …