Students’ Pre-Instructional Beliefs and Reasoning Strategies About Astrobiology Concepts

The purpose of this study is to identify and document student beliefs and reasoning difficulties concerning topics related to astrobiology. This was accomplished by surveying over two thousand middle school, high school, and college (science and non-science majors) students. Students were surveyed utilizing student-supplied response questions focused on the definition of life and its limitations. Careful, inductive analysis of student responses revealed that the majority of students correctly identify that liquid water is necessary for life and that life forms can exist without sunlight. However, many students incorrectly state that life cannot survive without oxygen. Furthermore, when students are asked to reason about life in extreme environments, they most often cite complex organisms (such as plants, animals, and humans) rather than the more ubiquitous microorganisms. Results of this study were used to inform the development of astrobiology curriculum materials. Astrobiology can be defined as the study of the origin, evolution, distribution, and destiny of life in the universe. It exists as an interdisciplinary science at the intersection of astronomy, biology, chemistry, mathematics, physics, and geology. Recent discoveries reported in both scientific journals and the popular press have dramatically changed our view of the potential for life existing elsewhere in the universe. As one example, nearly ten times as many planets have been discovered outside our solar system as there are within it. Perhaps even more impressive is that life has been found to exist under conditions previously thought impossible. This includes organisms that thrive in extreme temperatures, in highly acidic and basic conditions, at thousands of feet below Earth’s surface, on the dark ocean floor, and in the adverse radiation conditions of outer space (SpaceRef Interactive 2002). These discoveries are being made concurrently with discoveries that strongly suggest the existence of liquid water oceans beneath the icy surface of Jupiter’s moon Europa, and that running water was likely present on the surface of Mars in the past. As a result, our understanding of the limits on life has forever been changed. Because of astrobiology’s truly interdisciplinary nature, many classroom teachers are actively considering the inclusion of astrobiology concepts in their courses. As a result, there exists a growing need to create effective astrobiology teaching resources. However, there is a severe lack of documentation of the specific conceptual and reasoning difficulties students have when encountering astrobiology topics. Furthermore, there is also a serious absence of more fundamental research into students’ general preinstructional beliefs concerning such topics. The preliminary research project presented in this paper describes our efforts to uncover and document students’ beliefs about astrobiology-related topics prior to formal instruction. The results of this investigation were used to inform the development of a multitude of innovative, guided inquiry instructional materials in the field of astrobiology that are not described here. 1. BACKGROUND AND CONTEXT OF THE STUDY Contemporary efforts to create effective teaching resources have a long history of relying on an understanding of how people learn. The behaviorist view of learning, and consequently teaching materials, strongly influenced how learning was viewed during the early part of the twentieth century. Behaviorism focuses on the examination of students’ objective, observable behaviors rather than on the processes of the mind (Gardener 1987). Under this paradigm, teaching is conceived as creating a conditioned response in the student. For example, to teach a student about a complex process, teachers first break the process into its basic components. Next, the student is instructed on each of the individual components, followed by a demonstration of how each of the components is connected to the others. When the student has performed the “desired behavior,” he or she is deemed to have successfully “learned” the complex process. We now understand that this behavioral view of learning is insufficient. It ignores two critical aspects of the active learning process: (1) the importance of engaged mental effort used by the individual in learning a complex process/concept, and (2) whether the individual is able to accommodate the learned process/concept in a meaningful and appropriate way into his or her existing conceptualizations (Posner, Strike, Hewson, & Gertzog 1982). Fortunately, with targeted effort, teaching resources can be created to engender deep thinking in students if their pre-instructional beliefs are taken into consideration (Prather & Slater, in press). Our research questions are both motivated and guided by a constructivist view of the learning process. According to this perspective, students do not enter into the classroom as “blank slates” (Saunders 1992; Slater, Carpenter, & Safko 1993). Rather, new experiences and observations are actively interpreted and manipulated by students to create personal mental models of specific topics. The most important aspect of this viewpoint on learning is that students’ pre-instructional beliefs strongly influence the creation of their mental models and how prior experiences and observations become incorporated into these models (Redish 1994; von Glasserfield 1992). Consequently, the acquisition of new knowledge is highly dependent on (1) the topic under investigation, (2) the students’ prior exposure and experience with the topic, and (3) the instructional techniques used to introduce the topic (Prather 2000). In addition, students may even possess multiple and conflicting pre-instructional beliefs about the topic at hand. These beliefs may also simultaneously contradict and align with accepted scientific understandings of the topic. The more closely students’ pre-instructional beliefs are aligned with new experiences and observations, the greater the likelihood that new concepts will be accepted by the students, and in a manner consistent with the original intent. It is our belief that student learning will be enhanced by the use of instructional strategies that are guided by an understanding of the pre-instructional ideas students bring to the astrobiology classroom.