Revising geology labs to explicitly use the scientific method

Journal of Geoscience Education, Mar 2003 by Hannula, Kimberly A

ABSTRACT

Many content- or skill-based labs can be revised to explicitly involve the scientific method by asking students to propose hypotheses before making observations. Labs in which this method has been successfully applied include skill-building labs such as topographic map labs, content-based labs involving experiments with models, and field labs. Because these labs force students to state their expectations before making observations, they allow students to test their own models for various processes, making the students feel more engaged in the observations. Students' self-assessment shows that they felt that they learned a great deal from this style of labs, and that they found the abs to be fun. However, students felt that they learned little about the scientific method because they believed they already understood it, although other assessment methods suggest that their understanding was incomplete. By explicitly asking students to state and test hypotheses in the course of many labs, this type of exercise reinforces other discussions of the scientific method, and gives students a better understanding of how scientists think.

Keywords: Education - undergraduate, history and philosophy of science.

INTRODUCTION

Introductory geology courses frequently serve as general education courses that fulfill natural science graduation requirements. These introductory geology courses are, in many cases, the last exposure non-science majors will ever have to the natural sciences. Thus, geologists have the last opportunity to teach many members of the general public how scientists think.

The best way to learn how scientists think is to do science. That belief underlies lab science requirements at schools that require a lab course. Many introductory courses have added group research projects to their curriculum in order to force students to apply the scientific method, to learn to deal with ambiguous data, and to work in groups (e.g. Smith, 1995; Dunnivant and others, 1999). These projects can be the most worthwhile part of a student's introductory course experience, convince students that doing science can be fun, and turn students who considered themselves non-scientists into geology majors. However, for other students, these research projects are primarily exercises in frustration, as they struggle to simultaneously figure out what question he et ask, how to design a research project, and how to find mutually convenient times to meet with their research group. The logistical problems involved in a research project can become the students' primary focus, and the understanding of the scientific method may get lost beneath the details of when to meet and what to do.

The scientific method, alone, is fairly simple, however, and does not require a long, involved research project to be applied. At its most basic, the scientific method simply requires making a prediction and testing that prediction in a manner in which it can be falsified.

Most content-based geology labs (e.g., Busch, 2000; Tarbuck and others, 2000) involve students making some sort of observation, and then inferring something about more general geologic principles from their observations. This is typically the case whether in the field or indoor, and whether the lab involves using samples, maps, or experimental equipment. Scientists frequently work in this way; however, they also test the general principles they develop by making other observations. Unfortunately, in my experience, the weakest students are often confused by labs in which they are expected to infer general principles from their observations. Those students are unsure exactly what they are supposed to be observing, and they figure out the general priciples they are supposed to list as answers by asking their classmates, their TA, or their instructor, or by reading their textbook.

I have begun revising many of the labs that I use to explicityly involve the scientific method in short, content-based or skill-building labs as well as in longer research projects. This format has a number of advantages. It was originally devised to reinforce discussions of the scientific method by emphasizing how often it can be applied. In addition, it focuses students' attention on the concepts that they should understand as a result of the lab and shows students the application of techniques they learn in skill-building labs. By asking students about their expectations before they make observations, this format also provides a type of pre-assessment and an insight into students' pre-existing misconceptions. It also can help student re-examine their misunderstanding of some concepts. Finally, the students enjoy these labs, perhaps because it is fun to do experiments htn they have thought about what they expect to happen beforehand.

DESCRIPTION OF METHOD

Many existing labs can be revised to explicitly incorporate the scientific method. Every time the student is asked to make an observation, he or she is first asked to predict what the results of that observation might be. Depending on the background the student has in the subject before coming to lab, the student might be asked to justify his or her hypothesis before performing the test. Then, the student performs the test, in some cases following carefully prescribed steps and in others, choosing exactly which test to perform. The student records the results and then explains whether the results falsify or support the hypothesis. The student may or may not be asked to discuss the implications of the hypothesis further.