Teach the Earth > Early Earth > Teaching Uncertain Science

How do we teach about questions with no certain answers?

The ideas presented below were drawn from a group discussion at the Teaching Early Earth Workshop

"Early life is the poster child for uncertain science."
-Stanley Awramik, keynote speaker at the Teaching Early Earth Workshop

Observation vs. experimentation

An artist's rendering of a Mars rover exploring the surface of Mars. Image from NASA/JPL.

Geology is primarily an observational science; it relies heavily on first-hand accounts of processes and objects that we can see, touch and measure. However, many fundamental questions in Geology cannot be addressed by observation or experimentation, because earth systems evolve over space and time on a grand scale. For example, we can't run lab experiments to duplicate how the early atmosphere evolved, how the moon formed, or how the earth accreted. The key events that shaped the early earth have long passed and we will never be able to observe those processes. So how do we conduct our quest to unravel earths' early history?

Some strategies that scientists use are:

  • Draw comparisons from other planets, moons or solar systems.
  • Seek modern analogs, such as hydrothermal vents.
  • Use computer models to predict processes based on what we do know.
  • Conduct laboratory experiments on a small scale to test hypotheses about some of the chemical, physical and biological processes that may have been important in the early earth environment.

Employ a teaching strategy that capitalizes on the excitement of discovering something that is unknown.

On one hand, students crave the security of black and white answers. This is especially true for non-science majors. However, we can get students involved in the thrill of discovery and have them experience the process by which science expands or refines what is known. Faculty can embrace the uncertainty as a mechanism for getting students to explore and think.

The Crab Nebula. Image from the Hubble space telescope by NASA, ESA, CXC, JPL-Caltech, J. Hester and A. Loll (Arizona State Univ.), R. Gehrz (Univ. Minn.), and STScI
  • Have students 'discover' a controversy and the associated gap in knowledge.
  • Use the Socratic questioning method to lead a discussion of a question that may seem simple but that becomes increasingly complex upon closer examination.
  • Faculty can take on a guiding role in co-discovery. Instead of knowing the answers and disseminating that information, faculty are helping the class find answers. "I don't know but let's find out"
  • Start with concrete evidence and lead students to questions or areas of scientific controversy.
  • Start with the solid footing of what we already know, then guide students through further observations, formation of hypotheses and ideas for how the hypotheses could be tested.
  • Help students to understand the difference between a testable hypothesis and wild speculation.
  • Allow students to experience how the scientific process works and how scientists resolve conflict and solve tough problems.

Dealing with uncertain science can be daunting, so choose the topic and the approach carefully.

Living crinoids. Photo from the Smithsonian Museum of Natural History
  • Consider when students are ready for controversy. They need to have a solid foundation first.
  • What types of problems will be successful teaching examples? Some issues may be too controversial, such as the origin of life. It depends on the type of course and when in the course you are presenting uncertain science.
  • Choose a question that will be compelling with the students, such as something involving catastrophe, outside our experience, in the realm of science fiction, and so on.
  • Match knowledge gaps to the level of knowledge that the students already have.
  • Select a fairly focused issue rather than a wide-open mystery.
  • This is an important opportunity to help introductory students become more sophisticated in understanding that science isn't just a compilation of facts. There may be some resistance to this concept at first.
  • Emphasize that science is strong because we are continually refining the answers. Students will come to understand that not knowing (or being wrong initially) does not equal failure or "bad science."