September 2003
A wide variety of science-based issues for teaching can be found in a newspaper. Photo: Microsoft Image.
- “Anthrax vaccine: Controversy over safety and efficacy”
- “Shanghai issues new SARS regulation”
- “US to withdraw from Kyoto Global Warming Treaty”
- “Is the Endangered Species Act in danger?”
- “Brain disease rises in deer, scaring hunters”
- “UK to approve ‘therapeutic cloning’”
- “Born-again Quagga defies extinction”
- “President Bush and environmentalists disagree on forest fire policy”
One needs only to open a newspaper to identify a wide variety of science-based issues that can serve as an excellent vehicle for making science “come alive” for students. Using issues in the classroom also allows an instructor to foster the students’ skills of critical analysis and life-long learning that they need to deal with the changing nature of science in society. Providing students with the tools necessary to critically evaluate and make decisions about the future scientific issues they will face is central to scientific literacy education.
First case study: reformulated gasoline issue
In an introductory course in Environmental Science for undergraduate students (primarily for non-science majors) in our College Honors program, I posed the question:
“Should the Environmental Protection Agency have waived the reformulated gasoline requirement for Milwaukee [Wisconsin] in the summer of 2000?”
Reformulated gasoline (RFG) has oxygenating additives such as ethanol or MTBE that, at least in theory, decrease harmful emissions of ozone and ozone precursors (e.g., carbon monoxide, nitrogen oxides). Cities with ground-level ozone levels in excess of acceptable levels are mandated by the EPA to use RFG. In the summer of 2000, gasoline prices soared to over $2.00 per gallon, with the increase largely attributed to the RFG requirement. In response, several local governments sued the EPA to waive the requirement due to the wide-spread economic impact resulting from the increased fuel costs, combined with questions about the effectiveness of RFG.
The issue was chosen for four primary reasons:
- The course was taught in the fall of 2000, so the issue was very current and relevant in the minds of the students. They felt a direct stake in the issue every time they put gas in their car.
The issue involved a great deal of science. Students needed to understand what gasoline is and how it is made, the basic chemistry of combustion, the by-products of combustion, the biological implications of air pollution, etc. As with many scientific issues, the issue also involved a level of uncertainty that students had to deal with.
The issue had political, economic, and social ramifications. Students recognized a key ramification when they saw gas prices soar to over $2.00 per gallon, but also came to learn about how political decisions are made and the relationship between scientific evidence and public policy.
The issue had no clear answer. This helps students to understand that there isn’t always a “right” answer, and reinforces the importance of making informed decisions that are well-supported by evidence.
The unit was structured to emphasize student-led investigation. Students developed a list of what they felt they needed to understand in order to answer the question posed and brainstormed potential sources of that information. Class sessions included lectures, guest speakers, field trips, group presentations, and class discussions. Groups of students were responsible for researching topics such as:
- air quality regulations
- ethanol and MBTE
- the supply and distribution of reformulated gas
- the economics of reformulated gas
and then making presentations to the class as a whole. Class sessions were supplemented by readings from the National Academy of Sciences’ report on reformulated gasoline and readings from a general environmental science textbook. Laboratory sessions during this unit investigated the effects of ground-level ozone on milkweed leaves (Asclepias syriaca), which gave students an opportunity to experience the process of scientific investigation and why uncertainty is a part of all scientific endeavor.
I assessed student learning by evaluating:
- class presentations
- participation in discussions
- laboratory reports
- final papers in which they presented their “decision” on whether the EPA should have waived the reformulated gas requirement
- a written examination on the scientific concepts introduced in the unit
It is worth noting that my own background with respect to this issue was minimal, so I was learning with the students. This was advantageous in that I could model the value of life-long learning and I could clearly empathize with their struggle to come to grips with the ambiguity of the issue. On the other hand, students would certainly have traded my empathy for more guidance as they wrestled with what was a very difficult issue.
- The “reformulated gasoline” unit pushed students to critically analyze a contemporary environmental issue.
- In doing so, they had to learn a variety of scientific concepts and also how science is done.
- Most vividly, they wrestled with the role of uncertainty in science and how that uncertainty comes to play at the interface between science and public policy.
This was a difficult and frustrating unit for many of the non-science majors. Yet student evaluations and my own impressions suggested that despite the frustration, many students found value in the experience and came to appreciate that often policy decisions need to be made when supporting data are incomplete or there is not time for more research.
Perhaps most importantly, focusing on a current issue allowed the students to work through the type of process they’ll need to undertake when they are trying to analyze an issue they read in the newspaper someday, but to do so with a variety of academic support structures in place.
Second case study: zoology issues
To help students (primarily science majors) in a vertebrate zoology course build skills in finding and evaluating evidence and allow them to build connections between course material and the “real world,” I assigned a series of issue discussions throughout the one-semester course. Students selected three issues during the semester about which they would become the “experts.” Experts were responsible for researching the evidence on all sides of the issue, preparing a summary statement that explained the issue, using evidence to support a particular position on the issue, and, working with other experts, facilitating a class discussion on the issue.
The course was organized in units that focused on each major vertebrate class, and I assigned one issue in each unit. This constraint sometimes made it challenging to identify a strong issue about which there was true disagreement. Sample issues selected for the course included:
- “Aquatic exotics — what’s the fuss?” which focused on the problems with defining and assessing the impact of introduced fish species.
- “Are birds really feathered dinosaurs?” which assessed recent evidence on the origin of birds.
- “Don’t shoot Bambi — shoot his mom!” which looked at the strengths and weaknesses of various white-tailed deer herd management practices.
In their written and oral presentations, evidence of the following criteria was assessed:
- rigorous research
- a clear understanding of the issue and of the sources used
- critical thinking
- preparation and ability to teach classmates about the issue
- a logical structure to the paper and discussion
All of the students in the course agreed that the issue discussions were a valuable part of the class that helped them achieve the course objective of being able to “locate, synthesize, and discuss semi-technical scientific information about current issues in vertebrate zoology.” The most common criticism of the issue discussions was that the “experts” tended to focus more heavily on presentation, rather than discussion of the material.
What makes a good issue?
An issue is basically defined as a topic with no clearly-defined single outcome or answer — something about which reasonable people might be expected to disagree. Issues can also be framed in terms of a case study, particularly those known as “decision cases” or “dilemma cases,” or a problem, as in problem-based learning. Issues most useful for teaching science are characterized as “data-rich,” so students have an opportunity to consider and evaluate potentially contradictory evidence, as well as to understand how that evidence was generated. Often, data sets can be extracted from published literature, to allow students to work through the same decision-making strategies as the original researchers. Issues should also make clear connections to the course objectives with respect to both content and skills, and instructors should work to reinforce and support these connections through all phases of the educational process.
Although issues with contemporary relevance often best capture student interest, some historical issues provide useful educational opportunities as well. For example, the American Biology Teacher published an article entitled, “The Tragedy & Triumph of Minamata: The Paradigm for Understanding Ecological, Human-Environment & Culture-Technology Interactions.” Minamata disease is a neurological disorder caused by methylmercury poisoning, resulting from industrial waste being dumped into a marine system where there was an active fishing industry. Students could investigate a variety of biological (as well as social, political, and legal) concerns connected with this issue. Given the historical nature of this Japanese disaster in the 1950s and 1960s, students would also be able to see how the issues raised were actually resolved, one of the things that is difficult to do with contemporary issues.
Other excellent historical issues include:
- the recombinant DNA controversy of the late 1960s
- the regulation of clorofluorocarbons in the 1970s and 1980s
- the response of deer populations on the Kaibab plateau in Arizona, following the removal of major predators
- the attempt of Biosphere 2 to serve as a model of the Earth’s environment
- dinosaur extinctions and the significance of Mexico’s Chicxulub crater
- the spotted owl debate in the Pacific Northwest
The issues used in a science course can be simple or complex, depending on the goals of the course. The issue might be addressed in a single class session, over the course of several class sessions, for an entire unit, or even for an entire course. Issues can be taught with a heavy reliance on lecture/discussion or with the focus on independent or collaborative inquiry.
Reflections on teaching and learning with issues
In 1996, the National Research Council outlined key objectives for science literacy at the undergraduate level, indicating that students should:
- understand the basic principles used to explain natural phenomena
- connect science, mathematics, engineering, and technology to real world problems and issues
- understand the processes by which scientists, mathematicians, and engineers investigate and solve problems
- be exposed to information that is broad and current
- acquire the ability to remain life-long learners about these subjects2
This level of scientific literacy is seen as critical both for encouraging interested and talented students to pursue careers in science and for educating a citizenry prepared to critically evaluate and respond to the changing needs of society in an increasingly-technological future. “Science, mathematics, and technology are defined as much by what they do and how they do it as they are by the results they achieve.”3 Given this, providing students with a strong understanding of science entails more than providing them with a body of content. We need to encourage students to ask and answer their own questions, to evaluate and use evidence, to relate historical perspectives to current conditions, and to connect scientific evidence to social and political perspectives.3 Issue-based education provides an excellent vehicle for achieving these goals.
Incorporating issues into a course requires rethinking many aspects of the teaching and learning process.
Preparation: Instructors need to search diverse media sources — including journals, magazines, the Internet, and newspapers for appropriate issues. Instructors can also take advantage of an increasing number of resources now available with prepared issues in the form of case studies or problem-based learning activities (see “learn more” links at end of this article).
Developing skills: Issue-based education should build students’ core skills in:
- reading critically
- identifying important information and discriminating fact versus opinion
- identifying what is know and what is unknown
- locating and evaluating sources of evidence
- understanding scientific method and recognizing weaknesses in the design of scientific research (e.g., lack of replication, inadequate controls)
- framing data-rich arguments (e.g., using graphs effectively)
Instructors should intentionally build these skills by modeling the process they wish students to follow, or having students work on issues of increasing complexity as their skills improve.
- Leading the discussion: Student’s need a “road map” for how to find the information that they need to engage in the case; this changes the instructor’s role from one of gathering and disseminating the material directly. Students who feel uncomfortable with analyzing challenging data and evidence in a science-based case might tend to focus more on the social/political aspects of the issue, so instructors should be prepared to guide and direct students to achieve the objectives of the exercise. Instructors should also be prepared to relinquish a greater level of control in the classroom to give the students the freedom to wrestle with the issue in their own way.
- Assessing the outcomes: It is critical that instructors develop assessments directly connected to the objectives of the experience, which strengthens student motivation to acquire the essential analytical skills of the exercise. Structuring a formal outcome where students must make a decision and support it helps students to find closure on the issue, even if there is not a satisfactory “right answer.” At the same time, a well-defined grading rubric helps students understand that they are being evaluated on the quality of their analysis, rather than on whether they agree with the instructor’s views or not.
Educators in science often feel compelled to concentrate on the conveyance of vocabulary, facts, and concepts. As a result, they may rely fairly heavily on the lecture method of presentation. However, if we are truly committed to the objectives of science literacy, we need to also incorporate strategies to teach higher-order thinking skills. Issue-based education can serve that need. Dr. C. F. Herreid, Director of the Center for Case Study Education in Science at the State University of New York, Buffalo, notes that issue-based case studies in science:
“… involve learning by doing, the development of analytical and decision-making skills, the internalization of learning, learning how to grapple with messy real-life problems, the development of skills in oral communications, and often team work. It’s a rehearsal for life.”1
© 2003, American Institute of Biological Sciences. Educators have permission to reprint articles for classroom use; other users, please contact editor@actionbioscience.org for reprint permission. See reprint policy.
