MIDDLE AND HIGH SCHOOL TEACHER MISCONCEPTIONS OF GEOLOGIC TIME

Much time and attention has been spent on identifying and addressing student misconceptions in the K-12 science classroom. This investigation takes a look at misconceptions held by teachers relating to dates and spacing of geologic events. Previous studies have been conducted along this theme. For example, the Libarkin et al. (2007) results show that, “overall, the majority of college students understand the relative order of major biological events in Earth’s history, while misunderstanding the time span between events” (p. 421). For elementary school in-service teachers in the United Kingdom, Trend (2001) found similar results, that his participants seem to be familiar with the general relative order of biologic events in Earth’s history but not the placement of geologic events through time.

We wanted to see if the results seen in college undergraduates and U.K. teachers would hold true for grade 5-12 teachers. We took the Libarkin et al. (2007) survey and distributed it to seventeen Pennsylvania in-service middle school and high school teachers to document their conceptions of geological and biological events based on scale and time. The teachers were given a blank column on a page and asked to place numbers and words on the timeline for Earth Forms, First Life, Humans, Dino, and No Dino. The teachers were also asked to explain their responses.

All but one of the teachers were able to accurately list the order of events. When it came to the dates, only 41% knew the date of first life, 18% knew when dinosaurs appeared, 6% knew when dinosaurs went extinct, and 29% knew when humans first appeared. For the spacing of these events, none of the teachers were able to correctly plot the events along a timeline, even when they had the dates accurate. Approximately half of the teachers correctly plotted the location for first life. Half of the teachers also had the correct width of time between dinosaurs and no dinosaurs, yet none of the teachers plotted these two points at the correct location. Our survey demonstrates that in-service teachers currently hold misconceptions of the scale of geologic time, which may impact their understanding and instruction of deep time in teaching Earth Science history and processes.