Symposium: lecture and learning: Rre They Compatible?
Demonstration-Exploration-Discussion: Teaching chemistry with Discovery and Creativity Theodore L. Miller Ohio Wesleyan University, Delaware, Ohio 43015
This Journal recently created The Forum on teaching general chemistry ( I ) . For me the dilemma in general chemistry is more about the way we teach than about what we teach. I agree with George Bodner who said in his Forum paper, "Changing the curriculum-the topics being taught-is not enough to bring about meaningful change in science education, we also need to rethink the way the curriculum is delivered." (2).It's not so much what we talk about in class as what we do. In this paper I will outline the ways in which I have changed my delivery of chemistry and describe what I do to help students create and expand their own knowledge. When I first started teaching, my focus was on the material. Now, my focus is on the students. Before, I saw students as passive recipients of knowledge, but, now, I see students as creating their own knowledge. With my focus on material, learning was static. However, with my focus on the students, learning is dynamic. Learning is a process in which the instructor and students share getting to know more. I am now willing to learn from students: willing to listen, to wait, and to a h o w l e d g e student creativity. dver the past eight years, I have gradually replaced formal lectures with a more active and dynamic interaction with students. I now use what I call a demonstration-ex~lorationdiscussion format in my chemistry courses. I $11 develop the background for these changes in the following paragraphs. After participating in the 1983ADAPT Workshop (31, I revised the course materials for analytical chemistry using the learning cycle model presented in the workshop. The ADAPT model evolved out of the work of Piaeet and each learning cycle contains three steps: exploration, invention, and aoolication. The laboratorv work in analvtical chemistry served as the exploration step in some cycies and as the application step in others. Even though I could see the
value of the ADAPT method, the changes that I made were modest because I found it very difficult to give up lecture topics. However, the experience stimulated my interst in the learning process, and I continued to search for a better way to present chemistry to my students. After two Chautaugua courses on cognition and teaching with Ruth Day (4).I returned to the classroom with new lecture notes but I still wasn't satisfied. I felt stuck in the lecture model or, as Jane Tompkins puts it, in the performance model (5).
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Discussion
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A model for the demonstratior+exploratio~iscussion method
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The Genesis of the Method Finally, during the teaching of general chemistry over the past four years, the demonstration-exploration-discussion method began to crystallize. I started using more and more demonstrations during class after I discovered that the students could create concepts out of their participation in classroom activities. The classroom became a place to explore and evaluate, to create and synthesize, and to ask questions-an atmosphere, that from my point of view, promotes critical thinking while students learn a specific body of information. Overall, the structure of courses where I use the demonstration-exploration-discussion format is similar to most other chemistry courses. I give the students an assignment each day, collect homework, solve problems, discuss chemistry, perform demonstrations, have evaluations, give grades, etc. However, the environment for learning is different; inquiry is more important than answers. The interactions between the instructor and students foster creativity and promote a spirit of cooperation. The figure shows a model for the demonstration-exploration-discussion method. From the name the process may seem linear; going from demonstration to exploration to discussion. However, in practice it is much more dynamic. Discussiou can produce exploration, or it can lead to another demonstration. A demonstration can generate exploration, or it can precipitate discussion. The classroom activities center around demonstrations and student discovery. Discovery and creativity may occur at any of the intersections shownin the figure. Each day I bring a demonstration or series of demonstrations to class. There are several books ( 6 9 ) and, of course, the Tested Demonstrations sectionof this Journal for finding appropriate demonstrations. Sometimes I execute the procedure while the students observe. Sometimes students assist, or record data on the board. Sometimes I put a flask or other items in front of the room for investigation, or pass the items around for observation and testing. During the process students have an opportunity to practice being scientists: they observe, they discover, they formulate hypotheses, they test their hypotheses, they create, and they expand Table 1. Standardized Exam Results
Student Groupa
Number of Students Average Percentile Rank
'Group A-All of the studems in Analytical and General Chemistryfrorn 1974 to 1991. Group L T h e students using the demonstration-exploatioMiScu~~ion format from 1987 to 7991. GmuP C T h e students in traditional lecture courses fmm 197410 1990.
Table 2. Standardized Exam Results for Students in Parallel Sections
Year
Averagepercentile Rank Lecture Section D-E-D Sectiona
aDemonstation-exploratioMiscussion Section
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Journal of Chemical Education
their knowledge. The method is illustrated, using one of my favorite demonstrations, in the next paragraph. The Demonstration-Exploration-Disscussion Method in Action I use the Blue Bottle Demonstration (10) in several ways. I always put the Florence flask in front of the students and start bv askine them to call out their observations and invite them to come up and perform tests on the system whenever thev wish. 1 use this demonstration first tb let the students create the scientific method for themselves. ARer spending time observing, testing, concluding, and formulating hypotheses, we recall and write down the stem that were utilized. In the end we label the Drocess usid in this demonstration "the scientific method" and relate our "wientilic method" to how wc undertake many of our daily activities. Later in the year during our sessions on types of chemical reactions or gases, we return to explore the Blue Bottle system in more detail. Finally, during our investigation of kinetics, we work out a general reaction mechanism for this system. I have also incorporated the demonstration-exploration-discussion format into my evaluation process. I ask students to record their observations and develop conclusions for a demonstration done during class. In addition, I now use more open-ended questions on exams. For example, I ask them to discuss their approach to a problem or write a short essay on a specific topic. These questions give the students an opportunity to apply their classroom insights and discoveries in a new way and fosters creativity as well as ~mvidinea basis on which to evaluate their understanding of basic concepts. I have continued to use, as Dart of the final examination. tests re oared bv the Examinations Institute of the ~ i v i s i o nof~h&nical ducat ion of the American Chemical Society Scores are given as percentile ratings based on data from the National College Chemistry Testing Program. Although these examinations have some disadvantages, for me they offer an independent evaluation of student performance in my courses and they remove my personal bias from the determination.
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Evaluation of Student Performance Table 1summarizes the standardized test results for my students. There are too many variables (the long time span of data, different versions of the ACS exams, lack of controls, and etc.) to make firm conclusions about the demonstration-exploration-discussion format. However, the demonstration-exploration-discussion method of teaching chemistry appears to have had a very positive influence on student performance on the ACS exam. The results for two parallel sections using the ACS examination in general chemistry are shown in Table 2. At Ohio Wesleyan, we offer two or more parallel sections of general chemistry taught by differentfaculty members. All of the sections use the same syllabus, textbook, and grading scheme. The results in Table 2 show that the performance of the students in the two parallel sections is about the same on the ACS test. This would suggest that students who participate in a course taught using the demonstration-exploration-discussion method perform as well on standardized examinations as students who attend classical lectures where each topic is more explicitly covered by the teacher. Similar results were found in an experiment where students in a cooperative learning setting were evaluated using an exam written by an instructor in a parallel lecture section (2, 11). Observations of the Effects of the Method In conclusion I would hke to share some of my observations since the development of the demonstration-explora-
tion-discussion method and to sueeest an intemretation of these observations. Before using g e dernonstrckion-exploration-discussion method, I spent most of my time writing on and looking at the chalkboard in front of the mom. Now, I mend the samemost of mv time lookine at the students. I &all never forget the expression on &e student's face when he proposed his reaction mechanism for the system that we were exploring that day. The "Aha,I see!" that he felt was clear and his creation was aresent for us all. The experience vividly illustrated for the class how reaction mechanisms are determined hy chemists. Earlier, 1 would have presented an example of a reaction mechanism on the board and the opportunity for the class to practice being a sc~entistwould have been missed. The student's innovation might not have occurred, or not have been noticed. Overall, I have discovered that a classroom environment that fosters active student participation and creativity facilitates learning chemistry. The changes that I have initiated in mv teachinr! not onlv invoke active student aarticipation a i d creati;ty but radically alter the relathship between the teacher and the learner as well. The dialorme generated by the demonstration-exploration-discuss~on method replaces the teacher as the source of knowledge and the center of activity. Both the teacher and students learn that new ideas and creativity come out of this dialogue. We also learn to respect diversity, to work cooperatively, to ask questions, to explore, and to invent. We expenen& beiue scientists: we come to know that chemist& is a human a&ivity and ;lot just a bunch of abstract kndwledge. All of these extras come without loss in student per-
formance. However. there is a cost. We teachen must be willing to transforn; ourselves in the process. We must be willine our livine and our teachine out of a new -to overate . paradigm. Acknowledgement
I thank all of the students who have helped me develop the demonstation-exploration-discussion format. Their enthusiasm. understandine. and creativitv have been a source of inspiration for me.? also thank Ki& A. Lance and Joseah C. Stickler (currentlv at Vallev Citv State Colleee. valley City, ND) for sharing their stiden; results for ChL ACS exam. Literature Cited 1. J Chem. Edac. 1892.69.174. 2. Bodner, G. M'. Chem. Edue. 189%,89,186. 3. Fuller, I1. G.,Ed. Plogetian Rogmms in Higher Education, ADAPT; University of
NebresLa: Unmln, NE,1982. 4. Day, R. S. Cognitbn and Teaching fl m d IIJ; National Chautauqua Short Course R o p m . Lwnard Muldawer. Chairmw; Temple University: Philadelphia, PA 5. lbrnpluns, J.Col@Engllsh, 1880.32.653. 6. Humphreys. D. Dmonatroting Chemistry; Department of Che-*, Maaster University Hamilton, Ontario. Cananda, 1983. 7. Shafiashiri, B. 2. Chemrml D ~ m m t m f i oA~Hand&& , for m d m m ofChemistry: TheUnivsrsityafWhconsin:Madison, WS 1983,Vol. 1; 1985,Vol.2; 1989,Vol.
10. Duttan,F B.J.Chem.Edve 1~,37,AT99.&inTestod&mnatmbnsinChem-
&~~,6thed.:W-es,H.N.sndDuMn,FB.,E&.;JwmslofChe~cdalEdueat: Easton, PA, 1965; p 187. 11. Bodnu.G.M;Mstz,PA.;Tabii,KJ. J C k m E d u c . , inpresa.
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