In the Classroom
Eutrophication of Lake Wingra: A Chemistry-Based Environmental Science Module Ann C. Howe* Department of Mathematics and Science Education, North Carolina State University, Raleigh, NC 27695; *
[email protected] Leslie Cizmas and Robert Bereman Department of Chemistry, North Carolina State University, Raleigh, NC 27695
A recent comprehensive study of undergraduate education commissioned by the National Science Foundation, Shaping the Future (1), found that enrollments in science, mathematics, and technology are declining and that many undergraduates report negative reactions to courses in these disciplines. Among the reasons advanced for this decline is that science is taught in colleges and universities at the purely theoretical level with little attempt to relate what is taught to the world the students live in. Introductory chemistry is surely not exempt from this criticism, as Tobias (2), Cross (3), and others have noted. During the past two decades many institutions have sought to revise and improve undergraduate education in the sciences. Efforts have included a program to enhance curriculum coherence and interinstitutional program articulation (4), the development of interdisciplinary studies through cooperative efforts among science departments and between academic sciences and more applied fields (5), and the creation of an interdepartmental degree program (6 ). A recent article (7 ) describes an approach to general chemistry aimed at making chemistry relevant for students in applied programs. Although these efforts are encouraging, the lack of a significant body of literature on making chemistry more relevant to the lives of students makes it clear that much work remains to be done. Environmental Science Curriculum Module This paper describes the development and field test of a curriculum module that demonstrates how one topic in introductory chemistry, the reactions of phosphates, is related to a serious and common worldwide environmental problem, the eutrophication of freshwater lakes.1 Eutrophication is a process in which increasing levels of phosphorus, a plant nutrient, and decreasing levels of oxygen stimulate a variety of dramatic changes in the lake ecosystem. Rampant growth of algae, deterioration of water quality, the death of fish, and loss of the lake as a recreational resource are among the possible consequences. Lake Wingra in Madison, Wisconsin, is an example of a phosphorus-enriched lake that has undergone eutrophication. This lake was selected for a case study of eutrophication because it has been studied extensively and a large body of data is available to use as the basis for exercises included in the instructional materials. The curriculum module is organized into a student manual, an instructor’s manual, and a computer visualization component. The first chapter of the text materials covers such topics as the sources of phosphorus in lakes, forms of phosphorus found in lakes, phosphate cycling (phosphorus movement between the various living and nonliving components of the lake environment), the effect of anoxic sediment conditions 924
on release of phosphorus from the sediments, the effect of increased phosphorus on lake ecosystems, social and political issues to consider in addressing eutrophication, and methods for controlling eutrophication. Subsequent chapters examine in greater depth the chemistry, biology, ecology, politics, and management of this environmental problem. The goals of the module are these: (i) to give students a solid understanding of the causes and consequences of phosphorus-related eutrophication, (ii) to develop students’ analytical and problemsolving abilities through various exercises relating to the realworld problem of Lake Wingra, (iii) to increase students’ interest in and appreciation for science by showing how it is used to understand real-world problems, (iv) to engage students in an active learning process, and (v) to demonstrate that an interdisciplinary approach is essential in addressing complex environmental problems. Uses of Module in Other Courses Although the first section of the module is an introduction to phosphate chemistry, the materials may be used in a variety of courses, allowing instructors from other disciplines to show how their area of specialty relates to causes and solutions of environmental problems. Instructors may have students read the introductory chapter for a complete overview of the problem, then focus on any one of the subsequent chapters, depending on the focus of the course. These materials have also been used successfully in courses at various levels, from an introductory course at a community college to a graduate-level university course. To date the module has been used at North Carolina State University, Western Piedmont Community College, and Duke University. It has been taught in an introductory biology course, an environmental science and policy course for sophomores, an upper-level environmental science course, and a graduate-level environmental chemistry course. The written materials may be used as the basis for lectures or, in cases where the schedule provides adequate time, may be assigned as reading to be discussed in class. The exercises based on data from Lake Wingra supplement and reinforce the written material by giving students the opportunity to integrate the background material from various disciplines and use it to analyze a specific, real-world problem. The exercises include a computer visualization laboratory based on real data from Lake Wingra showing the amount of phosphorus entering the lake each month from various sources around the lake. Also included are directions for group activities and role playing that engage students in exploring the causes, consequences, and control of the eutrophication of Lake Wingra and encourage interaction between the instructor and students and among the students themselves.
Journal of Chemical Education • Vol. 76 No. 7 July 1999 • JChemEd.chem.wisc.edu
In the Classroom
A management planning exercise requires integration of information from various disciplines, leading students through the process they would follow to develop a management plan. This requires a solid understanding of the scientific aspects of eutrophication, including the chemistry of phosphorus in lakes, as well as understanding of social and political factors.
curriculum development. The main findings were these: 1. Work on the module required a serious commitment of time. Most team members had rearranged schedules to attend meetings and had spent from 250 to 300 hours on the project. 2. What team members valued most was the opportunity for professional collaboration with colleagues from other disciplines and institutions. Participation on the team was valued in and of itself aside from any knowledge gained or any use that might be made of the end product. 3. The leadership ability and commitment of the faculty member who led the group was a crucial factor in team members’ decisions to join the group and in their motivation to remain on the team. It is noteworthy that all members remained with the team throughout the process and eight of the nine respondents wrote that they would work on another similar module if given the opportunity.
Development Strategy The module was developed by an interinstitutional, interdisciplinary team that included faculty members from a research university, a primarily undergraduate university, a two-year community college, and a technical community college, a scientist from a research institute, two computer scientists from a computer research facility, and a staff member assigned to the project. Disciplines represented within the group included chemistry, biology, political science, environmental management, and computer visualization. The group met monthly throughout an academic year and communicated between meetings via email, telephone, and fax. Team members prepared drafts of chapters in their areas for review and discussion by the team; the computer visualization group met separately to develop materials that were reviewed and refined by the team. Some of the questions that guided the work of the team were these: What is unique about this module? What are the objectives ? What are the key concepts ? In what classes could the module be used? What experts should be consulted by the team? How can computer visualization reinforce or amplify the academic content?
At the end of the year during which the module was developed, team members were asked to respond to a set of questions designed to elicit their reactions to the team approach to
Student Evaluation of Module A questionnaire, using a 5-point scale with ratings ranging from high (5) to low (1), was developed to obtain student evaluations of the effectiveness of the module in accomplishing the goals stated above. The first step in evaluation was a field test, in which the unit was taught and evaluated by students by means of the questionnaire. As a result of the field test evaluation the module was revised and put in final form and the questionnaire was refined to provide more specific information. In the subsequent semester the module was taught in two courses. One was an environmental science and policy course for sophomores at a highly selective research university. The other was a biology course at a two-year community college. The results, by type of institution and with ratings combined as high (5, 4), Medium (3), and low (2, 1), are shown in Table 1.
Table 1. Student Rating of Eutrophication Module % of Students Respondinga Questionnaire Item A
High B
Medium A B
A
Low B
Statement of Effect of Module 1. Increased my interest in science.
36
69
44
19
20
12
2. Increased my understanding of science concepts of module. 3. Increased my understanding of value of different disciplines in understanding environmental problems. 4. Increased my knowledge of use of computer models by environmental scientists. 5. Computer visualization increased my understanding of scientific and political issues of the module. 6. Exercises increased my skills for working in groups.
73
94
24
6
2
0
84
75
13
19
2
6
36
75
47
12
16
12
38
75
24
12
38
12
40
75
49
19
11
6
7. Contribution of STELLA to understanding scientific issues.b
41
75
31
25
28
0
8. Overall rating of module.
80
80
18
20
4
0
1. Lecture
24
44
2. Handouts
42
25
3. Group Work
29
12
I did most of my learning through:
4. Homework
4
6
5. Other
0
12
aA rating of high corresponds to 5 or 4 on a scale of 1 to 5; medium corresponds to 3; low corresponds to 1 or 2. Columns labeled “A” represent students at a research university (N = 45); columns labeled “B” represent students at a 2-year community college (N = 16). bNot all students used STELLA, a computer program.
JChemEd.chem.wisc.edu • Vol. 76 No. 7 July 1999 • Journal of Chemical Education
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In the Classroom Table 2. Student Attitude toward Environmental Issues before and after Module Item
Time of Survey
1. Student’s level of interest in environmental problems.
Students Responding (No.) a Low
χ2 (df = 2)
High
Moderate
Before After
13 20
18 14
9 6
8.26*
2. Usefulness of scientific knowledge in solving environmental problems.
Before After
20 21
10 15
9 4
5.25
3. Student’s view of complexity of environmental problems.
Before After
13 22
17 17
10 2
4. Level of personal commitment to actions that are "environmentally friendly".
Before After
15 28
18 11
6 1
5. Level of interest in knowing more about environmental problems.
Before After
13 20
22 16
5 4
12.68* 19.9* 6.23*
NOTE: χ2crit = 5.99 at p = .05. The asterisk indicates values for χ2 greater than χ 2crit. aRatings are described as high = 5, moderate = 4, and low = 3, 2, 1.
Students in the two courses also responded to an attitude questionnaire, developed for this project, administered before and after the module was taught. A five-point scale with ratings ranging from high (5) to low (1) was presented. Response sheets for students who did not complete both pretest and posttest were discarded. Because of the frequency of only one or no ratings of 1 and 2, these were combined with rating 3 for the analysis. Although there appeared to be interesting differences between students in the two institutions, the number of cells with low frequencies made it impossible to analyze the data separately. The data for each item were entered into a 3 × 2 contingency table and subjected to chi square analysis, with the results shown in Table 2.
in a significant way, and can be adapted for use in courses other than chemistry. The participants’ positive evaluations of the interinstitutional, interdisciplinary approach to curriculum development and the outcomes of the student evaluations encourage us to continue to employ this model for the development of environmental science curriculum modules based on real data.
Summary
Note
The curriculum module developed by the interdisciplinary, interinstitutional team has been taught in four courses at three institutions. Student evaluations from two of these classes, one taught at a highly selective research university and the other at a two-year community college, are reported. Data from the attitude survey show that there was a significant increase in student interest in environmental problems and in their understanding of the complexity of environmental problems and a particularly striking increase in their level of commitment to “environmentally friendly” actions. Eighty per cent of students from both groups gave the module an overall high rating and 73%, and 94% of students attested to the module’s effectiveness in increasing their understanding of science concepts related to eutrophication and in helping them see the value of scientific knowledge in understanding environmental problems. We have shown the feasibility of developing a curriculum module that has a basis in real data, incorporates technology
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Acknowledgment This work was supported by grant DUE-9354599 from the National Science Foundation Division of Undergraduate Education.
1. The module is available from Robert Bereman, Box 8204, Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204.
Literature Cited 1. Advisory Committee to the National Science Foundation. Shaping the Future: New Expectations for Undergraduate Education in Science, Mathematics, Engineering, and Technology; National Science Foundation: Washington, DC, 1996. 2. Tobias, S. They’re Not Dumb, They’re Different; Research Corporation: Tucson, AZ, 1990. 3. Cross, R. Int. J. Sci. Educ. 1997, 4, 468. 4. Washington Center for the Improvement of the Quality of Undergraduate Education. Final Report to the Ford Foundation, 1986–88, Vol. II; 1988. 5. Mohrman, K. Innovations in Science Teaching; Forum for Liberal Education Series; American Association of Colleges: Washington, DC, February 1980. 6. Parker. O. J. J. Chem. Educ. 1990, 67, 327. 7. Juhl, L. J. Chem. Educ. 1996, 73, 72.
Journal of Chemical Education • Vol. 76 No. 7 July 1999 • JChemEd.chem.wisc.edu
