CTS Guide: Structure of the Solid Earth, pp 212-213- Section IV Research Summaries

Soil

• A study by Gosselin and Macklem-Hurst (2002) found that many preservice teachers believe soil is put down as rock layers, which may be the result of their focusing on horizons in a soil profile.

• Much of the research on children’s ideas about soil was conducted in New Zealand in the 1980s. Many New Zealand students believed soil was formed at the same time Earth was formed and has always been here. Even older students failed to explain how soil changes over time. When students were asked what soil is, they tended to use the terms dirt and soil synonymously. Many of the students in the study believed that soil goes through changes where it eventually becomes clay and then compresses into rock. When asked how deep soil goes, most students thought soil extended several kilometers into Earth (Happs 1982).

Earth’s Crust

• Children’s ideas about the Earth beneath their feet are influenced by their everyday experience digging holes. Few children have experienced digging holes greater than a few feet. When they have dug holes in the Earth or observed excavations, most children have seen soil with rocks in it (Russell et al. 1993).

• When Happs (1984) asked children how far down they thought soil would go if they dug down in their garden, their responses ranged from 6 in. to 10 miles. Some students suggested that soil would extend all the way to Earth’s core.