Activity pubs.acs.org/jchemeduc
Using Students’ Conceptions of Air To Evaluate a Guided-Inquiry Activity Classifying Matter Using Particulate Models D. Amanda Vilardo,† Ann H. MacKenzie,*,‡ and Ellen J. Yezierski§ †
Science Department, Sycamore High School, Cincinnati, Ohio 45242, United States Department of Teacher Education, Miami University, Oxford, Ohio 45056, United States § Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States ‡
S Supporting Information *
ABSTRACT: This paper describes a guided-inquiry activity designed for the first week of a first-year high school chemistry course. Students manipulated magnetic models of atoms in depicting air and learned to connect the three domains of chemistry: macroscopic, symbolic, and particulate. The purpose of the activity was 2fold: to remediate misconceptions of foundational chemical concepts such as atoms, molecules, compounds, subscripts, and coefficients; and to help students begin to think in the particulate domain of Johnstone’s triangle when studying chemistry. On the basis of curricula in prior years of science instruction, students should have relatively accurate models for air upon entering chemistry. This, in alignment with the literature reviewed, was not found to be the case. Students’ pretreatment and post-treatment drawings of the particulate nature of air were categorized and analyzed, demonstrating major shifts toward accurate particulate models of air after active engagement in the guided-inquiry activity. The majority of students’ drawings created prior to the activity depicted no particulate nature of air, and only 31% of the students’ drawings depicted the macroscopic domain nature of air. After the activity, 72% of the students drew the particulate nature of air correctly. This finding points to the value of guided inquiry using models in developing correct understandings of key chemistry concepts. KEYWORDS: High School/Introductory Chemistry, Analogies/Transfer, Hands-On Learning/Manipulatives, Inquiry-Based/Discovery Learning, Misconceptions/Discrepant Events, Constructivism
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INTRODUCTION
According to constructivist theory, knowledge and ideas are unique to the learner, which suggests that the learner’s environment and prior knowledge are just as important as the content being presented.9 For this activity, students have previously constructed knowledge of air due to past experiences and interactions. Students first studied that all matter is made of atoms in grade six, according to state standards in Ohio. Additionally, students participating in the study had experience with “air” when studying Earth and Earth’s atmosphere in the middle grades. Here we describe and evaluate an activity designed to build accurate ideas about the classification of matter aimed at exploring the depth of knowledge students have about the particulate nature of air, according to their preconceived ideas, and how student ideas change as a result of the activity. This activity adds to the repository of J, Chem. Educ. papers from the Target Inquiry projects focusing on the particulate level of representation.10−12 In addition to Target Inquiry activities, other publications demonstrate a similar emphasis.13−15
Traditional chemistry instruction usually includes students listening to lectures that present known facts, followed by laboratory sessions in which students verify these facts.1,2 In recent years, a plethora of research has shown that these traditional methods are not optimal for student comprehension3,4 and should be altered. Research done by Johnstone2 and Gabel4 shows that meaningful learning happens when students make connections among all three domains of chemistry: macroscopic, symbolic, and particulate.5−7 The problem is that many first-year chemistry students do not understand how or why to use the three domains listed above. Research by Krajcik6 and by Stains and Talanquer7 states that students often misunderstand foundational chemical concepts at the beginning of their studies, which leads to larger misconceptions and other difficulties as students graduate to more difficult chemical concepts. Krajcik6 and Gabel8 also state that if students are to understand chemistry, then they must understand foundational chemical concepts and learn to connect Johnstone’s domains at the beginning of their course work. Understanding foundational chemical concepts while connecting all three of Johnstone’s domains provides an easier transition into more difficult concepts for all students. © XXXX American Chemical Society and Division of Chemical Education, Inc.
Received: February 13, 2016 Revised: September 16, 2016
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DOI: 10.1021/acs.jchemed.5b01011 J. Chem. Educ. XXXX, XXX, XXX−XXX
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Activity
METHODS
of matter. After students draw their second picture of air, they are asked to reflect on their drawings. This activity spans a 70 min period of time with the prelab drawing done at the beginning and the postlab drawing at the end of this block of time. A few student reflections are referenced in the Results section of this paper. Student answers were reviewed to gain insights about the drawings and improve the validity of the interpretation of the drawings. The activity was implemented according to the instructor guide that accompanies the student guide from the Target Inquiry Web site.16
Activity Overview and Data Collection
The purpose of this activity titled What’s the Matter? is 2-fold. First, the activity is designed to address common misconceptions related to the classification of matter, which is foundational to many chemical concepts. This includes differentiation between atoms, elements, compounds, molecules, and mixtures. Stains and Talanquer7 state that common student misconceptions include that elements and atoms are the same thing, diatomic molecules represent compounds, compounds and mixtures are the same thing, and confusion between coefficients and subscripts. The second purpose of the activity is to provide an introduction to learning in the particulate domain of Johnstone’s triangle. The prelab of this activity includes students’ drawing their interpretations of “air”, and a discussion of matter versus nonmatter. During this time, student-led small group discussions followed by teacher-led whole group discussions take place. Students have the opportunity to revisit their “air” drawings at the end of the activity. The activity then has students build specific models [using circular magnets some of which were blue (B), green (Gr), and red (Rd)] from six different formulas (Figure 1). After manipulating and building
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DATA ANALYSIS An analysis of student “air” drawings generated before and after the activity was done to assess the enhancement in student depth of knowledge of the particulate domain and foundational chemical concepts due to this activity. Student drawings were placed into 10 categories and validated by 10 high school chemistry teachers of varying backgrounds and degrees of education who collaborated and negotiated their categories and re-sorted the drawings until consensus was reached. No interrater reliability was calculated; the process was more holistic and generative in nature. The categories emerged from grouping drawings based on similarities and differences. The categories encompass a wide range of ideas and conceptual understandings. Criteria used to determine categories were based upon the analysis of the students’ understanding of the particulate domain after completing this activity.
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RESULTS AND DISCUSSION Table 1 shows the categories ranked from lowest to highest conceptual sophistication, with category 10 being the highest. If a student’s drawing is classified as category 3 before the activity, and the same student generates a drawing after the activity that fits into category 9, then we conclude that this student’s understanding has improved her conceptual understanding. Pretreatment and post-treatment categorizations of drawings are shown in Figure 2. The data in Figure 2 show the categories for students’ pretreatment and post-treatment air drawings. Results suggest this activity greatly improved student depth of knowledge of foundational chemical concepts, as well as introduced or, perhaps, taught students what chemistry means according to the particulate nature of matter. For instance, in the preassessment 37% of students (N = 58) expressed air in the macroscopic domain, and only 31% expressed air in the particulate domain. Of the 31%, none of the students correctly drew air; these drawings were mostly nonbonding small circles as seen in Table 1. It is not surprising that 22 students drew particulate representations that lacked correct bond formation and structural detail. Students had not yet learned about electron structure or bonding when this lesson was implemented. Expressing air in a largely macroscopic way suggests students do not have an understanding of the particulate nature of matter, and perhaps have a superficial understanding of foundational chemical concepts such as atoms, molecules, and compounds. Post-treatment assessments show that 72% of students expressed air in the particulate nature of matter, with 71% showing bonding between particles and diatomic elements. The last question of the activity asked students to “Discuss the similarities and differences in the first
Figure 1. Students working with magnet “particles” to create models of air.
models, students are asked guided questions helping them visualize the “particulate nature of matter” while correcting any misconceptions of foundational chemical concepts. • How many different types of atoms are there in this group? • In the formula “B2”, what does the subscript “2” represent? Are the 2 B atoms connected? • In the formula “2 Gr” what does the coefficient “2” represent? Are the 2 Gr atoms connected? • Why is there not a whole number coefficient in front of Rd3? • Are the B2 and Rd3 particles atoms? Why or why not? • Are the 2 Gr particles atoms? Why or why not? • The three models in this group can all be described with a single word. What are each of the particles in this group? • Are molecules two or more atoms of the same element, or different element, that are chemically bonded together? • Which particles that you built could be described as molecules? At the end of the activity, students are asked to complete a concept map, to aid in visualizing differentiated types of particles. The postlab includes students drawing another picture of “air” based on their new knowledge of the particulate nature B
DOI: 10.1021/acs.jchemed.5b01011 J. Chem. Educ. XXXX, XXX, XXX−XXX
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Table 1. Categories of Students’ Level of Conceptual Understanding Shown in Drawings of Air
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DOI: 10.1021/acs.jchemed.5b01011 J. Chem. Educ. XXXX, XXX, XXX−XXX
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Figure 2. Distribution of students by category of their particulate drawing of air.
approach by building models of air assisted students in expanding their knowledge of the particulate nature of matter. By connecting Johnstone’s domains1 at the beginning of chemistry course work, students can create a strong foundation that will guide them as they pursue more difficult concepts in chemistry.
and second drawing (of air). What new knowledge did you gain?” Some insightful student responses are as follows: • “At first I didn’t draw anything because you can’t see air but now I know it is a mixture of multiple atoms and molecules.” • “I drew a bunch of separate atoms in the first one. I learned that it is actually a mixture of elements and compounds.” • “The first drawing I had air as nothing, now I know air consists of compounds, elements, molecules, and atoms. I also learned how to read compounds and the difference between a coefficient and a subscript.” It seems student responses and data from the study support recent research that student misconceptions about foundational chemical concepts will improve while using the particulate nature of matter during instruction, particularly using the activity evaluated here.
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LIMITATIONS Directions given to students in the prelab activity do not state what air is specifically composed of (oxygen, nitrogen, hydrogen, etc.), yet in the postlab activity students are told that air is specifically composed of nitrogen (N2), oxygen (O2), carbon dioxide (CO2), and argon (Ar). The past experience of one of us (D.A.V.) with students showed they could list the components of air, albeit incorrectly in chemical composition and abundance, indicating to the teacher that students already knew that air was a mixture of substances. D.A.V. developed the activity, recognizing that students did not have a method for modeling these ideas. It is therefore not surprising that students opted to use macroscopic representations before the activity and particulate ones after the activity. The size, rigidity, shape, and color of the models may convey ideas to students that are not consistent with the types of matter that models are supposed to depict. During the activity, D.A.V. did not discuss the limitations of the magnets as models for atoms. Further implementation of the activity should include how the magnets differ from real atoms as well as the
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CONCLUSIONS This inquiry activity helped students with little background knowledge on learning in the particulate domain in chemistry form examples and ideas of the particulate nature of matter. Student drawings of air reflected an improvement in their depth of knowledge regarding foundational chemical concepts and the particulate nature of matter. Before the activity 31% expressed air in the particulate domain. After the activity 72% used particulate representations to depict air. Using a guided-inquiry D
DOI: 10.1021/acs.jchemed.5b01011 J. Chem. Educ. XXXX, XXX, XXX−XXX
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(4) Gabel, D. Enhancing Students’ Conceptual Understanding of Chemistry. In Chemists’ Guide to Effective Teaching; Pienta, N. J., Cooper, M. M., Greenbowe, T., Eds.; Pearson: Upper Saddle River, NJ, 2005; p 77. (5) Bruck, L.; Towns, M. Preparing Students To Benefit from Inquiry-Based Activities in the Chemistry Laboratory: Guidelines and Suggestions. J. Chem. Educ. 2009, 86 (7), 820. (6) Krajcik, J. S. Developing Students’ Understanding of Chemical Concepts. In The Psychology of Learning Science; Glynn, S., Yeaney, R., Brinnon, B. K., Eds.; Albeum: Hilldale, NJ, 1990; pp 117−148. (7) Stains, M.; Talanquer, V. Classification of Chemical Substances Using Particulate Representa−tions of Matter: An Analysis of Student Thinking. Int. J. Sci. Educ. 2007, 29 (5), 643−661. (8) Gabel, D. L. Use of the Particle Nature of Matter in Developing Conceptual Understanding. J. Chem. Educ. 1993, 70 (3), 193. (9) Bodner, G. M. Constructivism: A Theory of Knowledge. J. Chem. Educ. 1986, 63 (10), 873−878. (10) Herrington, D. G.; Luxford, K.; Yezierski, E. J. Target Inquiry: Helping Teachers Use a Research Experience To Transform Their Teaching Practices. J. Chem. Educ. 2012, 89 (4), 442−448. (11) Putti, A. JCE Classroom Activity #109: My Acid Can Beat Up Your Acid! J. Chem. Educ. 2011, 88 (9), 1278−1280. (12) Cullen, D. M. Modeling Instruction: A Learning Progression That Makes High School Chemistry More Coherent to Students. J. Chem. Educ. 2015, 92 (8), 1269−1272. (13) Ortiz Nieves, E. L.; Barreto, R.; Medina, Z. Classroom Activity #111: Redox Reactions in Three Representations. J. Chem. Educ. 2012, 89 (5), 643−645. (14) Cullen, D. M. Modeling Instruction: A Learning Progression That Makes High School Chemistry More Coherent to Students. J. Chem. Educ. 2015, 92 (8), 1269−1272. (15) Dukerich, L. Applying Modeling Instruction to High School Chemistry To Improve Students’ Conceptual Understanding. J. Chem. Educ. 2015, 92 (8), 1315−1319. (16) Target Inquiry at Miami University. http://www.targetinquirymu. org/ (accessed Sept 2016).
value of using models to illustrate and communicate different particulate level ideas of matter.
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FUTURE WORK Future applications of this work could be tracking students’ progress through an entire first-year chemistry course, using this activity at the beginning of the course, and continuing to employ all three of Johnstone’s domains.1,2 Other drawings could be pretreatment and post-treatment diagrams of dissociation of ions in water or gas particles under pressure. Also, retention of foundational chemical concepts could be studied by having students draw air at the very end of the course, and then analyze these with the same criteria. Perhaps another study could be done using a control group, not exposed to the particulate domain of Johnstone’s triangle, to compare and contrast knowledge of foundational chemical concepts after the course is over. Practitioners may have students compare and contrast their drawings or go as far as categorize them as was done in this study. The most straightforward application of this work includes teachers using this lesson in their classrooms. A complete teacher student guide can be accessed for free.16 The teacher guide includes preparation instructions, teaching tips, facilitation hints, and an end-of-activity assessment. The authors appreciate any feedback users have after they have implemented the activity.
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ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available on the ACS Publications website at DOI: 10.1021/acs.jchemed.5b01011. Student guide (PDF) Instructor guide (PDF)
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AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. Notes
Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the National Science Foundation or Miami University. The authors declare no competing financial interest.
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ACKNOWLEDGMENTS We thank D.A.V.’s students for participating in the study as well as teacher colleagues from Target Inquiry at Miami University, and the Yezierski Research Group in the Department of Chemistry & Biochemistry at Miami University. This material is based upon work supported by the National Science Foundation under Grant 1118749.
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REFERENCES
(1) Johnstone, A. H. The Development of Chemistry Teaching: A Changing Response to Changing Demand. J. Chem. Educ. 1993, 70 (9), 701−705. (2) Johnstone, A. H. You Can’t Get There from Here. J. Chem. Educ. 2010, 87 (1), 22−29. (3) Domin, D. A Review of Laboratory Instruction Styles. J. Chem. Educ. 1999, 76 (4), 543−547. E
DOI: 10.1021/acs.jchemed.5b01011 J. Chem. Educ. XXXX, XXX, XXX−XXX
