Research: Science & Education
Integrating Multiple Teaching Methods into a General Chemistry Classroom Joseph S. Francisco and Gayle Nicoll Department of Chemistry, Purdue University, West Lafayette, IN 47907 Marcella Trautmann Department of Chemistry, Wayne State University, Detroit, MI 48202 In many undergraduate general chemistry classrooms, the lecture is the dominant teaching mode. It is characterized by the instructor speaking and writing at the front of the class while the students busily take notes at their desks. This teacher-centered mode of instruction has the advantage of being able to cover large amounts of material, but it does not ensure that the students learn or understand the material (1). Indeed, studies of students’ misconceptions (2) have yielded insights into the ways students learn material. This, in turn, has led to the suggestion of several different modes of teaching to address these chemical misconceptions, including cooperative learning (3), classroom discussions (4), and concept maps (5). A number of studies have shown that expectations of the faculty and the students are not in accord. Students do not feel in charge of their own learning; instead, they feel that their understanding and their grades are in the hands of the professor (6). The professor, on the other hand, believes that students should be in control of their learning, so that any type of instruction should be as good as any other. However, research has shown that students learn by different methods (7, 8), which must all be addressed if learning is to be successful and fruitful. Conceived this way, the traditional lecture format ignores educational theories that point out the advantages of actively involving students in the learning process and the need for varying the means and taxonomic levels of the teaching goals (9, 10). The lecture format does have useful purposes, and some students can be actively involved in lecture. However, as it is often practiced, the lecture method misses the opportunity to more immediately involve students in learning the material during class and passes up the chance to show students how to engage in chemistry.
Alternative methods of instruction have been successfully implemented in science classrooms with successful results, including increased student understanding of the material. Very few studies, however, have attempted to integrate more than one teaching method into the course (11). We found no published report that described application of multiple teaching styles to college-level general chemistry courses. The purpose of this study, then, is to use four different methods of teaching in a freshman-level general chemistry course at Wayne State University. Cooperative learning, class discussions, concept maps, and lectures were integrated into the course to compare students’ levels of participation, as measured by a self-reported survey. Methodology The study involved 94 students enrolled in a freshmanlevel second-semester general chemistry course at Wayne State University, a commuter campus in the heart of urban Detroit, Michigan. The class met three times per week for 50 min per session. The class was used as a whole: sections or subgroups did not exist. Therefore, every student was exposed to all of the teaching strategies at the same time. The class was composed of approximately 69% men and 31% women; 18% of the students were African-Americans. For the entire semester, three interactive teaching formats were meshed with the lecture format. Table 1 shows how the teaching formats were integrated into the curriculum for two units of the semester. In each unit, all four types of teaching were used, which minimized any effects due to the subject matter. The first format, class discussions, allowed the professor to question students in the classroom in ways that probed
Table 1. Sample of Integrating Teaching Formats in General Chemistry Session Teaching Format 1
Topic To Be Covered Introduction; Chemical equilibrium
2
Lecture
Chemical equilibrium; Acid–base equilibrium
3
Cooperative learning
Strong acids and bases
4
Class discussion
Concepts of weak acids and bases
5
Lecture, Cooperative learning Solubility equilibria
6
Concept map
7
Exam
––
8
Class discussion
Applications of solubility equilibria
9
Lecture
Thermochemistry
Cooperative learning
Thermochemistry
10
210
Lecture
Complex-ion equilibria
11
Lecture
Thermodynamics (1st and 2nd laws)
12
Class discussion
Thermodynamics (3rd law and free energy)
13
Concept map
Thermodynamics (free energy and equilibrium constants)
14
Exam
––
Journal of Chemical Education • Vol. 75 No. 2 February 1998 • JChemEd.chem.wisc.edu
Research: Science & Education for understanding and required the use of higher-level cognitive functioning. This was distinctly different from the traditional lecture format, in that students were actively engaged. In the lecture format, simple problems were presented and solved to illustrate how the concepts were used, what the results looked like, and what the results meant. There is a difference, however, between how the professor solved these problems and how students solved the same problems. Instead of lecturing for the entire session, the professor used leading questions in class discussions not only to get students involved, but also to guide their thinking about the pertinent chemistry concepts. In addition, the professor roamed through the lecture hall asking and directing questions. Although the professor was still the center of the classroom, students immediately influenced the direction and content of the lecture. Class discussions related the material to other issues in chemistry, modeled more integrative and creative ways of looking at the material, and promoted the active working and reworking of the learned material by students. The dialogue between students and professor has several other merits. It allows students to think about concepts and make sense of the material. The professor begins to model how students conceptualize the material. This reminds the professor that students’ chemical knowledge is a product of their thought patterns. The end result is a concept meaningful to the students, and the whole class is engaged in the construction of a significant concept. To illustrate how the professor engaged students in class discussions, we present the following example, which was used during the unit on thermodynamics. After covering
the laws of thermodynamics, presenting fundamental relationships from the laws, and working simple problems in the lecture, the professor held a class discussion during the next session. The following questions were posed to the students. It’s a very hot day in Texas, and the air conditioner in your house has broken! A member of your family suggests that you open up the refrigerator to cool the house. Do you agree with your family member or not? Would this work? Why or why not?
The professor then directed the discussion by allowing students to reflect on the laws of thermodynamics and how they relate to heat flow. During the discussion, the professor challenged the students’ assumptions, directing them to examine the inconsistencies in their reasoning. This allowed them to evaluate and correct their own cognitive structures. The second method, cooperative learning, engaged students in solving problems as a group during the class hour. During the hour, students arranged themselves into informal groups usually consisting of five or six students seated near each other. Students took turns playing the role of instructor in their groups and taught others how to complete derivations and problems. Most students could replicate a calculation similar to one solved in the previous lecture period, provided that the new problem explicitly used the same concept and formulas. However, more challenging problems were presented, which required students to disembed information from the problem. These problems used concepts and formulas from the lecture, but were presented in novel ways that were not obviously algorithmic. The following is a typical problem posed for students to work on in their groups. It requires application of chemical
Figure 1. A modified concept map presented to students for the unit on thermochemistry. Students were encouraged to study the map and integrate it with key words from the concept map on equilibria, to obtain a larger picture of how chemical concepts are interrelated.
JChemEd.chem.wisc.edu • Vol. 75 No. 2 February 1998 • Journal of Chemical Education
211
Research: Science & Education principles and conceptual problem-solving skills. Students were encouraged to add to, correct, or extend the work of their classmates by offering alternatives. By working actively and collaboratively with problems, students came to realize that they could reason, evaluate solutions, and develop self-confidence to take greater responsibility for their education. The chief chemist of Trautmann Chemical Works, Ltd., interviews two chemistry majors for employment. The chief chemist states, “Quality control requires that the pH of a solution of potassium cyanide, KCN, is maintained at pH = 11.2.” The pKa = 9.40. The chief chemist asks the two interviewees what must be done to ensure that the company meets this specification. Mr. Max Smart says, “I would just add 0.10 moles of potassium cyanide to 1 liter of water and use a pH meter to determine the pH to ± 0.01 pH units and interface it with the IBM computer to print out the pH digitally.” Mr. Joe Wise says, “I would titrate the KCN with a 0.10 M solution of HCl and use phenolphthalein to detect the equivalence point.” Which candidate did the chief chemist hire? Why?
The third teaching format, concept maps, drew students’ attention to the hierarchical nature of chemistry and the need to pull together material from individual chapters and lecture series. Concept map sessions were held as review sessions before exams. During these review sessions, students were asked to identify relationships, compare and contrast topics, and integrate information into larger conceptual maps. Figure 1 shows a typical concept map used in these sessions. This helped students see how topics relate to, or develop from, each other to produce chemistry’s cumulative nature. For example, during the unit on equilibrium chemistry, students first constructed a map using some basic principles of equilibrium such as the definition of equilibrium, the equilibrium expression, the equilibrium constant, and heterogeneous and homogeneous equilibrium. Later, a concept map was constructed using acid–base equilibrium and was connected to the original concept map of basic principles. By using this building process, students constructed one large concept map by the end of the semester, showing the interconnectedness among topics.
Table 2. Student Involvement for Each Type of Teaching Perceived level Format of involvement Lecture
2.5
Concept mapping
3.3
Class discussion
4.1
Cooperative learning
3.3
Note: An ANOVA found a significant difference between the lecture and nontraditional teaching methods, but not between the nontraditional methods themselves: N = 94; F = 4.25, p < .01.
Results and Discussion At the end of the semester, students were asked to specify how directly involved they felt in all of the segments. This was done to assess their reception to and perceived involvement in the various teaching strategies. In order for a teaching strategy to be effective, as a first step it must be well received. Therefore, it was important to determine what the students perceived as the utility of the strategy. This can be broken down into two components: how engaged students perceived themselves to be in the strategies, and what they perceived to be the functions of each method. Should student engagement or the perceived functions be the same for all teaching strategies, then the effectiveness of these strategies would be extremely suspect. A 7-point modified Likert scale was used to assess student involvement, where 1 represented no involvement at all and 7 represented extreme involvement. The average involvement levels of the students for each teaching method, shown in Figure 2, were then compared using an ANOVA to determine if there was a significantly different level of involvement for the methods. The students reported a significantly higher involvement in each of the three new types of teaching (Table 2) than in the traditional lecture format. However, a follow up showed no significant difference in the perceived levels of involvement between the
Table 3. Student Perception of Primary Function of Teaching Methods Teaching Method Functiona Mean level of involvement
Concept map
Provided new information Assessed readiness for the next topic Assessed readiness for the next exam Organized material in meaningful ways
Class discussion
Identified a lack of understanding Answered questions about the material Organized material in meaningful ways Made the material more interesting Relearn concepts
Cooperative learning Lecture Lecture
212
Pin-pointed concepts Clarified important or difficult points
Class Concept Cooperative discussions map learning
Figure 2. Student perception of involvement for various teaching methods. Involvement was self-estimated on a 1–7 Likert scale; 1 = no involvement and 7 = extreme involvement.
Made the material more interesting
Organized material in meaningful ways Modeled ways to look at the material Relearn concepts a The
functions are listed in no particular order.
Journal of Chemical Education • Vol. 75 No. 2 February 1998 • JChemEd.chem.wisc.edu
Research: Science & Education nontraditional teaching methods. Figure 2 shows the average level of reported involvement for each teaching method. From these data, it is evident that the method which encouraged the most class participation was the class discussion. All three methods, however, had a significantly greater level of student involvement than the traditional lecture. Students were also given a survey in which they were asked to identify the functions that each teaching format served for them. They were allowed to list more than one function for each method. The functions listed were (i) provided new information, (ii) pinpointed important or difficult concepts, (iii) identified a lack of understanding of certain points, (iv) clarified important or difficult points, (v) answered questions regarding the material, (vi) organized material in meaningful ways, (vii) modeled ways to look at the material, (viii) made the material more interesting, (ix) provided the opportunity to relearn concepts, (x) assessed your readiness for the next topic, and (xi) assessed your readiness for the next exam. It was found that each teaching format served a different purpose for the students. Table 3 shows which functions were perceived as most important for each format. It is evident that students found the concept map review format helpful in preparing them for the exam. Oddly, however, the concept map reviews were also useful for providing them with new information. This is another piece of evidence showing that students do not necessarily learn information the first time through and that multiple, varied presentations are necessary before they can form their own more integrated cognitive structures. The lecture format, on the other hand, was helpful to students in pinpointing important concepts. However, it was through the class discussions that they identified their lack of understanding of certain points. Cooperative learning helped them clarify important points. From the student data on formats versus functions, responses were condensed into three categories, depending on whether the functions were to (i) present facts, (ii) aid in metacognitive (thinking) processes, or (iii) create interest. To determine if there was any difference between the methods in addressing each of these types of learning, a chi-square analysis was done. Comparing the methods individually, in the students’ perception there was no difference among the four methods at presenting facts or aiding meta-cognitive processes (χ2 = 0.5, not significant at the p < 0.05 level). However, compared with the traditional lecture, the other three teaching methods were more effective at aiding metacognitive processes than at presenting pure facts (χ2 = 9.25, p < 0.01). These data suggest that the nontraditional teaching methods did not hinder student learning, as all methods were similar in the type of information students believed they gleaned from the sessions. As these are only means, the numbers do not state whether individual students preferred one method over another, or whether students generally felt the same about the teaching methods. It is evident, however, that presenting a varied classroom environment helps with all students’ learning, especially their perceived meta-cognitive processes. From Table 2 we see that there are several cognitive functions which students perceive as necessary to insure their
mastery of general chemistry. Further, all of the teaching methods do not serve the same learning functions. Thus, the data suggest that instructors’ use of only one mode of classroom presentation could restrict students by limiting their exposure to diverse learning situations that would help them identify topics that they don’t understand. Bodner (12) pointed out that very little mention is made of the role teachers play in the learning of chemistry by students. This criticism points to the need for use of more effective and interactive teaching methods. Our finding is consistent with this point, but we also find that the instructor should attempt to use or introduce interactive methods that provide cognitive balance for students. Conclusions Despite claims that student quality has decreased in the past few years, the data presented here indicate that the integration of multiple methods of teaching can enhance student participation. The data support the idea that multiple modes of learning foster meta-cognitive skills necessary for mastering general chemistry. In this way students are presented with material in different ways, which reinforces the concepts and aids mastery of the material. The classroom today is more diverse, and as a result there is diversity in the cognitive skills that students bring into it. Our data indicate that a mono-modal method of teaching is insufficient to meet all the learning needs of students as they attempt to master general chemistry. This is consistent with the findings of Birk and Foster (13) who found that little substantial learning occurs as a result of students attending chemistry lectures. Although students in our study stated that the lecture format was useful for communicating some information, it was not the preferred mode of learning. However, we found that the use of multiple teaching strategies in the classroom improved the chances for the instructor to tap into the cognitive strengths of a diverse student population. Literature Cited 1. Duit, R. In The Psychology of Learning Science; Glynn, S.; Yeany, R.; Britton, B., Eds.; Lawrence Earlbaum Associates: Hillsdale, NJ, 1991; pp 65–85. 2. Nakhleh, M. B. J. Chem. Educ. 1992, 69, 191–196. 3. Lazarowitz, R. Sci. Ed. 1988, 72, 475–487. 4. Deutch, C. E. Am. Biol. Teach. 1995, 57, 101–105. 5. Lawless, C. Br. J. Ed. Technol. 1994, 25(3), 198–216. 6. Carter, C. S.; Brickhouse, N. W. J. Chem. Educ. 1989, 66, 223–225. 7. Willemsen, E. W. New Direct. Teach. Learn. 1995, 61, 15–22. 8. Lenehan, M. J. College Student Develop. 1994, 35, 461–466. 9. Champagne, A. B.; Bunce, D. M. In The Psychology of Learning Science; Glynn, S.; Yeany, R.; Britton, B., Eds.; Lawrence Earlbaum Associates: Hillsdale, NJ, 1991; pp 21–41. 10. Roth, K. J. In Dimensions of Thinking and Cognitive Instruction; Jones, B. F.; Idol, L., Eds.; Lawrence Earlbaum Associates: Hillsdale, NJ, 1990; pp 157–175. 11. Caston, J. J. The Learning Experience: Impact on Measures of Institutional Effectiveness. Presented at “Leadership 2000,” the 16th Annual International Conference of the League for Innovation in the Community College and the Community College Leadership Program; San Diego, CA, July 17–20, 1994; ERIC #ED375907. 12. Bodner, G. M. J. Chem. Educ. 1992, 69, 186–190. 13. Birk, J. P.; Foster, J. J Chem. Educ. 1993, 70, 180–182.
JChemEd.chem.wisc.edu • Vol. 75 No. 2 February 1998 • Journal of Chemical Education
213
