In the Classroom
A Variation on the Use of Interactive Anonymous Quizzes in the Chemistry Classroom Brian D. Wagner Department of Chemistry, University of Prince Edward Island, Charlottetown, PEI, Canada C1A 4P3;
[email protected] There is a compelling need for the use of interactive methods in the university science classroom. In an eloquent article published in this Journal more than 15 years ago, Bodner made a convincing argument that “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” (1). Active-learning methods provide an alternative approach to curriculum delivery, toward the goal of further engaging students in the classroom through direct participation. Research evidence has shown the effectiveness of active-learning methods (2). Although there is no single definition of active learning, a simple working definition is “any learning activity engaged in by students in a classroom other than listening passively to an instructor’s lecture” (3). There are, of course, impediments to the implementation of active-learning methods in university classrooms and, in particular, science classes. Challenges include the limited time available for covering the content, large class sizes, time required to explain the activities (with which the students may be unfamiliar), the time commitment required to prepare activities, and varied student backgrounds (particularly in service courses). Approaches to overcoming these challenges have been discussed in the literature (4, 5) and include bracketing in-class active learning with mini-lectures, reducing lecture detail and specific content (when possible, without affecting the curriculum!), and including the active-learning activities in the grading scheme (5). Interactive anonymous quizzes, or IAQs, are an excellent tool for introducing an interactive component into large university science classes and for enhancing student engagement. They were first introduced as ConcepTests by E. Mazur for use in the physics classroom (6), and later further developed as IAQs by Thomas Holme for use in large general chemistry lectures (7). They are relatively simple to prepare, implement, and explain; work for any size class; take only a small quantity of time in the classroom; and address the major concerns with active-learning methods. Essentially, IAQs consist of a multiple-choice question that is displayed on the board or screen. This question, as described by Mazur and Holme, is generally designed to review the topic(s) covered in the previous class. Students are given two minutes to read the question and consider their answer. At the end of two minutes, they are asked to write down their answer from a selection of five choices identified with letters, along with a confidence factor: 1 for very confident, 2 if somewhat confident, and 3 if they are just guessing. Once every student has written an answer (or entered their answer using a “clicker”), they are then given three minutes to discuss their answer with their neighbors. In particular, if a student finds others around her or him with a different answer, then she or he is expected to try to convince the others that she or he is correct and that the others should change their answer. At the end of the three minutes of peer interaction and discussion, each student writes down a second answer, along with an updated confidence level. 1300
This second answer can be the same as the first one or a different answer. The instructor then collects the scraps of paper for analysis after class and then discusses the question and answer with the class. The students do not put their names on these scraps of paper, hence the anonymity aspect of the IAQ method that makes this a safe and low-risk interactive activity for the students. The use of IAQs has been shown to be effective for increasing engagement in large classes and also to provide useful feedback to the instructor (6, 7). I have found another application of IAQs, beyond that described by Mazur and Holme for reviewing material and assessing student learning. I use this variation of the IAQ as a method for introducing new sections of a course and as a stimulating bridge, or segue, between topics within a course. I find this technique to be particularly effective in my second-year environmental chemistry class, which is a midsize class of typically 40–60 students. In this article, I will present and describe two examples from this classroom application and also discuss students’ results. Furthermore, I have also used this teaching tool in my second-year physical chemistry class, with similar success, and will present and briefly discuss one example to illustrate the applicability of this method to any class or topic. Examples and Discussion At the beginning of the environmental chemistry course section dealing with acid rain, I introduce this new topic by presenting the students with the following IAQ: IAQ #1 The phenomenon of acid rain was first observed and reported in England in the (a) 1870s (b) 1920s (c) 1940s (d) 1950s (e) 1970s
The correct answer is (a). The Scottish chemist Robert Angus Smith studied the effects of the acidification of precipitation in the mid-19th century (8, 9); he not only used the term “acid rain” (9) in a book published in 1872 (10), but correctly traced its origin to sulfur emissions from the massive quantity of coal being burned for heat and for steam engines (8). After the students have had the opportunity to predict the correct answer, discuss this question with their peers and perhaps revise their answer, and hand in their answers, we begin a classroom discussion of the question. After my presentation of the correct answer, I ask the class why this might make sense from a historical perspective. There are always at least a few students who use the provided clue of England to make the connection
Journal of Chemical Education • Vol. 86 No. 11 November 2009 • www.JCE.DivCHED.org • © Division of Chemical Education
In the Classroom
to the Industrial Revolution and to the concomitant heavy use of coal. Once this connection is made and shared by these students, there is a definite moment of understanding by the rest of the class. A lively and interesting discussion always ensues. This IAQ helps to emphasize the anthropogenic sources of acid rain and the long history of the impact of human activity on the environment. I then begin my detailed discussion of the phenomenon and chemistry of acid rain. The class results obtained for this IAQ over five recent academic years are shown in Table 1.1 As can be seen from these data, the majority of students do not answer this IAQ correctly, even after peer discussion. This is a reflection of the nature of this question, which is not a review of material previously presented, but rather an introduction to new material with which the students are generally unfamiliar. In fact, the percentage of correct answers for the IAQs that I am proposing tend to be lower than those described by Holme, which reviewed material (7). However, the percentage of correct answers has usually increased after peer discussion (i.e., between the 1st and 2nd round of answers), illustrating the positive impact of peer discussion. However, in year C, there was a decrease in the percentage of correct answers, with more students with initially correct answers convinced to change to a wrong answer than vice versa. This specific outcome illustrates the need for instructor-led discussions at the conclusion of the IAQ so that not only will everyone know the correct answer, but will also understand the reasoning behind it.
The second example comes from the section of the course on pesticides and other toxic organic compounds in the environment. I first introduce the concept of toxicity and discuss measures of toxicity, in particular LD50 (the lethal dose for 50% of the test animal population in mg/kg test body weight). Before we discuss relative toxicity of various compounds of environmental concern, I present the following IAQ: IAQ #2 Which of the following substances has the lowest LD50 value? (a) aspirin (b) DDT (c) nicotine (d) caffeine (e) ethanol
The correct answer in this case is (c). The approximate LD50 values in terms of order of magnitude in mg/kg are 1,000 for aspirin and ethanol; 100 for caffeine and DDT; and 1 for nicotine (11). The class responses to this IAQ over five years are shown in Table 2.
Table 1. Environmental Chemistry Class Responses to IAQ #1 over Five Years Response
Year A
Year B
Year C
Year D
Year E
Total Number
48
57
56
53
50
Number CC (%)
16 (33)
8 (14)
12 (21)
10 (19)
7 (14)
Number IC (%)
5 (10)
6 (10)
5 (8.9)
6 (11)
6 (12)
Number CI (%)
0 (0)
1 (1.8)
7 (12)
1 (1.9)
5 (10)
Number II (%)
27 (56)
42 (74)
32 (57)
36 (68)
32 (64)
Correct 1st round (%)
33
16
34
21
24
Correct 2nd round (%)
44
25
30
30
26
Note: 1st round refers to individual response before peer discussion; 2nd round refers to response after peer discussion; CC = correct response both rounds; CI = correct response after 1st round changed to incorrect response; IC = incorrect response changed to correct response; II = incorrect response both before and after peer consultation (with no distinction between unchanged incorrect responses and incorrect responses changed to another incorrect response).
Table 2. Environmental Chemistry Class Responses to IAQ #2 over Five Years Response
Year A
Year B
Year C
Year D
Year E
Total Number
38
44
45
48
42
Number CC (%)
3 (7.9)
9 (20)
5 (11)
6 (12)
7 (17)
Number IC (%)
6 (16)
12 (27)
1 (2.2)
1 (2.1)
6 (14)
Number CI (%)
2 (5.3)
1 (2.2)
2 (4.4)
3 (6.3)
2 (4.8)
Number II (%)
27 (71)
22 (50)
37 (82)
38 (79)
27 (64)
Correct 1st round (%)
14
23
16
19
21
Correct 2nd round (%)
24
48
13
15
31
Note: 1st round refers to individual response before peer discussion; 2nd round refers to response after peer discussion; CC = correct response both rounds; CI = correct response after 1st round changed to incorrect response; IC = incorrect response changed to correct response; II = incorrect response both before and after peer consultation (with no distinction between unchanged incorrect responses and incorrect responses changed to another incorrect response).
© Division of Chemical Education • www.JCE.DivCHED.org • Vol. 86 No. 11 November 2009 • Journal of Chemical Education
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In the Classroom
This IAQ is fairly complex, as it tests not only the students’ preconception of the toxicity of various substances, but also tests their understanding of the definition of LD50, and in particular the idea that the higher the toxicity, the lower the LD50 value. In this case, there is a wide variation in the percentage of correct answers after peer discussion in different years, ranging from a low of 13% to a high of 48%. Similarly to the results obtained for IAQ #1, the majority of the students do not get the correct answer, even after peer discussion. This is once again a reflection of the variation on the traditional type of IAQ that I am proposing: an IAQ that presents material that is new to most of the students. Again, there is a general trend of an increase in the percentage of correct answers after peer evaluation; however, this time with both year C and year D as exceptions. A lively discussion of the relative LD50’s of these substances always follows this IAQ, with students expressing great surprise that nicotine is much more toxic than DDT, based on LD50’s. It is interesting to note that in the two years that the percentage of correct answers decreased, the final results were in fact below 20%, the statistically expected result if all of the students were simply guessing, suggesting that the students particularly avoided nicotine as the correct answer! This often leads to a discussion of the risks associated with tobacco smoke. We then proceed to a discussion of the relative toxicity of various chlorinated organic compounds, including DDT, PCBs, and PCDDs. As a final example of the range and versatility of this classroom tool, I present an IAQ used in the second-year physical chemistry course just before the introduction of Gibbs energy: IAQ #3 Which of the following processes at constant T and P can never occur at any temperature (i.e., is always non-spontaneous)? (a) an exothermic reaction with negative ΔrS (b) an exothermic reaction with positive ΔrS (c) an endothermic reaction with negative ΔrS (d) an endothermic reaction with positive ΔrS
(I will leave this question as a challenge for the reader to come up with the correct answer!) This example represents yet another way of using IAQs: instead of reviewing previous course material as in the approach of Mazur and Holme or introducing new material as illustrated by the first two IAQ examples, it is designed to review and combine concepts from a previous course, namely, introductory chemistry. Furthermore, answering this IAQ involves a higher cognitive process on the part of the students than simple recall, as described by Bloom’s taxonomy of educational objectives (12–14). The concepts of enthalpy and entropy, and their relationship to spontaneity, must be recognized, remembered, and combined to answer this question. This IAQ provides an example of “synthesis”, the sixth out of seven levels in Bloom’s hierarchy of cognitive processes that requires students to make connections between different pieces of information (14). In this example, the combination of the dependence of spontaneity on enthalpy and entropy provides a natural segue to a discussion
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of the concept of Gibbs energy and its significance. Reaching the higher cognitive levels is essential to the development and promotion of students’ critical thinking skills (14). It is useful to compare this proposed use of IAQs to another interactive technique for introducing new material, namely, guided inquiry, the use of which has been described in this Journal, both in the chemistry classroom (15) and laboratory (16). In guided inquiry, certain carefully chosen information is provided to the students, who are then led through a process of discovery to a deep understanding of the material. While guided inquiry is an elegant and pedagogically rich approach, it requires a tremendous level of careful planning, is relatively time consuming to implement, and requires a significant level of student “buy-in”. The use of IAQs, on the other hand, provides a simpler alternative that has the advantage of being easier to prepare and implement, requires less class time, and is a low-risk modification to any teaching approach. As a final note, IAQs represent an excellent technique to use with “clickers” or personal response systems. This approach maintains anonymity (at least among peers, although the instructor could see the responses of individual students using the clicker codes), saves paper (an appropriate attribute for an environmental chemistry class), and provides instant analysis (no need for the instructor to compile the results after class). The use of clickers in undergraduate physics classes using a related type of interactive-engagement quiz (without the peer discussion) has been described by Bray and Sarty (17). Summary IAQs are a valuable tool for promoting active learning in the university (or high school) science classroom. They are simple to design, prepare, and implement and do not take up much class time. They represent a low-risk active-learning strategy from the perspective of both the students (anonymity of the individual answers increases the comfort level) and the instructor (ease and time-efficiency of implementation). In the main variation proposed in this article, IAQs provide a unique way to introduce a new topic in class, while providing the instructor with an indication of the pre-existing knowledge level of the students on the topic of interest. These proposed IAQs introduce new material to the students and they promote critical thinking and spark discussion (and sometimes debate) by the students. The pedagogical value of using IAQs to introduce a new topic lies in the promotion of active learning within a traditional-lecture approach; the promotion and facilitation of group discussion and peer learning of a new topic; and the opportunity provided to students to make connections between various concepts and ideas of which they may have prior knowledge. With the guidance of the instructor (once the correct answer is revealed), further discussions and thought-provoking conversations can then ensue. It is suggested that this new variation of IAQs be used sporadically throughout a course (perhaps three or four times in a semester) as an interactive alternative to pre-assigned readings (or even as a pre-cursor exercise to inform and guide the selection for a subsequent reading assignment). In this way, IAQs can be effectively used to help promote an engaged and interactive chemistry classroom environment.
Journal of Chemical Education • Vol. 86 No. 11 November 2009 • www.JCE.DivCHED.org • © Division of Chemical Education
In the Classroom
Acknowledgments The author acknowledges Maryam Wagner for reading and commenting on the drafts, an anonymous referee for suggesting the connection to cognitive levels, all of the participants in the Faculty Development Summer Institute at the University of Prince Edward Island over the past few years (with whom I implemented IAQ #1), and to all of my environmental chemistry students, whose enthusiasm and interesting comments helped to hone and develop this approach to interactive teaching. Note 1. Although the students were asked to indicate their confidence levels, as in the case of the original application of IAQs for reviewing material (6, 7), these confidence data were not compiled or analyzed, as it was not clear what value such an analysis would have in the current application of introducing new material.
Literature Cited 1. Bodner, G. M. J. Chem. Educ. 1992, 69, 186–190. 2. Michael, J. Advan. Physiol. Educ. 2006, 30, 159–167. 3. Faust, J. L.; Paulson, D. R. J. Excell. College Teach. 1998, 9, 3–24. 4. The Teaching Professor 2002, 16, 1–3. 5. McClanahan, E. B.; McClanahan, L. L. College Teaching 2002, 50, 92–96.
6. Mazur, E. Peer Instruction: A User’s Manual; Prentice-Hall: Upper Saddle River, NJ, 1997. 7. Holme, T. J. Chem. Educ. 1998, 75, 574–576. 8. Gorham, E. Environ. Sci. Policy 1998, 1, 153–166. 9. Seip, H. M. Cicerone 2001, 6, 1–7. 10. Smith, R. A. Air and Rain: The Beginnings of a Chemical Climatology; Longmans, Green: London, 1872. 11. Baird, C.; Cann, M. Environmental Chemistry, 3rd ed.; W. H. Freeman: New York, 2005. 12. Bloom, B. S. Taxonomy of Educational Objectives: The Classification of Educational Goals. Handbook I: Cognitive Domain, 1st ed.; Longmans, Green: New York, 1956. 13. Pungente, M. D.; Badger, R. A. J. Chem. Educ. 2003, 80, 779– 784. 14. Warner, I. M. J. Chem. Educ. 2004, 81, 1413. 15. Lewis, S. E.; Lewis, J. E. J. Chem. Educ. 2005, 82, 135–139. 16. Gaddis, B. A.; Schoffstall, A. M. J. Chem. Educ. 2007, 84, 848–851. 17. Bray, J. M.; Sarty, A. J. Can. Undergrad. Phys. J. 2004, 11, 7–10.
Supporting JCE Online Material http://www.jce.divched.org/Journal/Issues/2009/Nov/abs1300.html Abstract and keywords Full text (PDF) with links to cited JCE articles
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