Article pubs.acs.org/jchemeduc
Evidence for the Effectiveness of Inquiry-Based, Particulate-Level Instruction on Conceptions of the Particulate Nature of Matter Chad A. Bridle*,† and Ellen J. Yezierski‡ †
Science Department, Grandville High School, Grandville, Michigan 49418, United States Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio 45056, United States
‡
ABSTRACT: Research has shown that students in traditional college-preparatory chemistry courses become masters of mathematical equations without an understanding of the conceptual basis for the mathematical relationships. This problem is rooted not only in what curriculum is presented to students, but also in how it is experienced by the students. Ample evidence exists in support of both inquiry-based instruction and the use of particulate-level models in instruction as a means for improving students’ conceptual understandings in chemistry. Little evidence exists, though, for the effectiveness of an instructional model that involves the merger of these two methods. In an effort to address this gap, a series of laboratory and classroom activities was created that blended guided inquiry-based instructional practices with particulate-level modeling experiences. The content of the curriculum focused exclusively on phases of matter and chemical versus physical changes in matter. This research explores the novel curriculum’s effect on student understanding of the particulate nature of matter in two sections of high school chemistry. Qualitative and quantitative evidence supporting the curriculum is presented. KEYWORDS: High School/Introductory Chemistry, Chemical Education Research, Hands-On Learning/Manipulatives, Inquiry-Based/Discovery Learning, Constructivism FEATURE: Chemical Education Research
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INTRODUCTION Chemistry students have long demonstrated their ability to solve algebraic problems without a clear understanding of the conceptual background of the problem.1−4 This lack of a scientifically accurate conceptual framework for the very foundations of chemistry is not only a problem by itself, but its effects extend into all other aspects of student performance in chemistry.5 Two different approaches to this issue have been explored: curriculum focused on particulate-level representations of matter,6,7 and inquiry-based instructional models.8,9 This paper describes the implementation and effectiveness of a novel curriculum that merges particulate-level modeling with inquiry-based instruction.
Because the particulate world of chemistry is invisible and theoretical, descriptions of this level must include models. In using models, the ability of the learner to comprehend the meaning of the model must be considered. Harrison and Treagust describe three different ability levels.12 At the most basic level, learners interpret models as exact replicas of reality. Thus, an atom that is represented as a red circle actually is a red circle. As modeling ability increases, students become better at differentiating between what a model is intended to show about a situation and the limitations of the model. In a later study, Harrison and Treagust describe a successful method for employing atomic models in instruction.13 Their work showed that part of the instructional process must involve exploring and discussing the merits and limitations of a particular model. Similarly, students bring varying degrees of understanding about the basic behaviors of matter. As far as incorrect conceptions about atoms and molecules, students frequently struggle with size, shape, and composition.14 These misconceptions include the assumption that one can see atoms and molecules under a microscope, that their volume and weight can change depending on conditions, and, for example, that water molecules can contain atoms other than hydrogen and oxygen. This lack of clarity leads to struggles with classification of matter, such as being able to distinguish between compounds and mixtures.15 Considering physical changes in matter,
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BACKGROUND Johnstone describes the three different levels of representation in chemistry: macroscopic, submicroscopic, and symbolic.10 A particulate understanding of atoms and their properties is central to explaining any concept that is observed or described on the macroscopic or symbolic levels.11 The importance of a strong understanding of the particulate nature of matter must be considered carefully. How do we appropriately represent and describe the particulate level? What sort of prior knowledge of the particulate level do students bring to the classroom? How do instructors properly guide their students to an appropriate understanding of the particulate nature of matter? © 2011 American Chemical Society and Division of Chemical Education, Inc.
Published: December 14, 2011 192
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Table 1. Summary of Inquiry Activities Implemented Inquiry Activity Putting the World in a Box Change You Can Believe In The Only Thing Constant in Life Is Change
Instructional Time, Min.
Description Constructing an understanding of appropriate particulate-level modeling. Establishing particulate-level descriptions of solids, liquids, gases, elements, compounds, and mixtures. Establishing appropriate methods for categorizing matter. Establishing clear, particulate-level definitions for physical changes and chemical changes.
120
Establishing an appropriate connection between particulate-level definitions of physical and chemical changes, and macroscopic observations.
120
90
development, but also the philosophies of science research.24 Learners and researchers alike approach a new situation with their current conceptual framework. Any new information or findings may not fit with their current framework. Individuals must then construct a new framework that accommodates the new knowledge and can be accepted as reasonable and useful. The process of constructing a true, correct understanding of the nature of matter allows students to more accurately describe any novel situations they may experience within and beyond chemistry. This approach to chemistry instruction, grounded in constructivist learning theories, necessitates the use of instructional and laboratory techniques that allow students to explore and find meaning in a given situation.20
common misconceptions include the idea that boiling liquids involves the expansion of molecules or even the breaking and forming of chemical bonds within the molecules.16,17 Lastly, these misconceptions lead to students’ inability to distinguish clearly between physical and chemical changes in matter.18 This evidence suggests that appropriate instruction in this field is a matter of constructing a correct conceptual framework within the minds of the students and not simply memorizing facts and processes. Using inquiry-based instructional approaches in chemistry has been proven effective. Hewson and Hewson used inquiry instruction in the design and implementation of curriculum regarding the concepts of mass, volume, and density.19 They found a statistically significant improvement not only in correct conceptual understandings, but also in a reduced number of misconceptions. Similar positive results were found by Lewis and Lewis upon implementing a peer-led guided inquiry curriculum.9 The literature shows that both particulate-level instruction and inquiry-based pedagogy improve students’ conceptual understanding of chemistry. Gabel suggested both methods for improving conceptual understanding, but little research exists regarding the merger of these two instructional models.20 The evidence within the literature merits the exploration of the fusion of the two methods in a novel inquiry-based, particulatelevel curriculum.
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RESEARCH DESIGN This pilot study aimed to investigate the effectiveness of inquiry-based, particulate modeling experiences in improving students’ conceptual understanding of chemistry. Using a quasiexperimental, primarily quantitative study with a one-group pretest−posttest design,25 the intervention engaged students in inquiry-based activities with various particulate-level representations of matter early in the school year. The curriculum implemented in the study was designed by a team of chemistry educators as part of Grand Valley State University’s Target Inquiry teacher professional development program. The classroom activities were designed to be used in the first few weeks of an introductory chemistry course. These laboratory experiences were intended to provide students with a strong particulate-level, conceptually based understanding of the basic behaviors of matter, better equipping them for further learning activities in chemistry.
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THEORETICAL FRAMEWORK The design of the intervention and the overall study is guided by learning theories grounded in work by Piaget and more recent constructivist points of view, including the conceptual change model. DeBoer noted that the purpose of science education goes beyond simply supplying students with facts and figures.21 Students must be able to think like scientists: effectively using their scientific knowledge, carefully studying and observing their world, and developing new understandings from these observations. Piaget’s theory of how humans constructed knowledge caused educators to reconsider how content was delivered. Prior models of instruction assumed that the information presented by the teacher was simply transferred to students, as though they were a blank sheet of paper waiting to be filled. Piaget forced educators to consider learning from the learner’s perspective. He believed that not only did each learner construct his or her own understanding of a subject individually, but also that any new knowledge had to be integrated with the learner’s current framework of understanding.22 In regard to the particulate nature of matter, students cannot simply be given information about the invisible particulate universe and be expected to accept it. Instead, students must explore and construct their own understandings of the topic so that a specific representation of the atomic level fits with their understandings of the world.23 This model for instruction parallels not only Piaget’s theory of student
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CONTEXT The novel curriculum was implemented in two high school chemistry sections in a large, suburban high school in the Midwest United States. One of the authors (Bridle) was the instructor for the two chemistry sections that were studied. Both sections were exposed to the same curriculum; data were not compared to a control group or established norms. The population in 3rd hour, n = 26, included 13 female and 13 male participants, while the population in 4th hour, n = 28, consisted of 13 female and 15 male participants. The participants were 15−17 years old, predominantly Caucasian and middle class. The curriculum was implemented during five and one-half 60min instructional periods over a three-week period as described in Table 1.
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DESCRIPTION OF INTERVENTIONS
Describing and Categorizing Matter Using Particulate-Level Models
The teacher guide and student guide for Putting the World in a Box26 are available as cited through the Target Inquiry Web 193
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chemical changes cards. A more traditional laboratory approach would have students make macroscopic observations and then ask them to relate these observations to the particulate level. This second activity reversed this process. Students have already categorized the laboratory activities as physical or chemical changes in the previous activity. For example, the students would have classified the process in Figure 1 as a chemical change. When this reaction is performed in the laboratory, one observation students would make would be the evolution of a gas. Students then make macroscopic observations of all of the processes illustrated in the cards and analyze their observations to determine the usefulness of each type of observation in defining an observed process as physical or chemical. For example, students would consider whether the evolution of a gas was a sign of a physical change, a chemical change, both, or neither. In the case of gas evolution, whether the production of steam, a gas, from boiling water fits this same category caused students to consider limitations and precise definitions for their macroscopic observations. This alternative approach forced students to use macroscopic observations as tools for constructing a model of particulatelevel behavior. A more traditional approach may have led students to consider the production of a gas, for example, as a definitive sign of a chemical change. The new approach results in students concluding that particulate-level definitions of physical and chemical changes are much more reliable descriptors of macroscopic processes.
site. This activity was designed to specifically target misconceptions related to the description and categorization of matter. The content addressed in this activity was the students’ first exposure to particulate-level models in their chemistry course. The literature describes students’ varying abilities to appropriately interact with models and how this may affect student learning regarding particulate-level instruction.12,13 As a result, a significant portion of the activity calls for students to explore the usefulness and limitations of various particulate-level representations of matter such that students may construct an understanding of the particulate-level behaviors of solids, liquids, and gases as they relate to observable, macroscopic behaviors. Second, the students use a similar approach to establish particulate- and macroscopic-level knowledge of elements, compounds, and mixtures. Lastly, the activity aims to merge these two knowledge structures in an effort to establish appropriate procedures for describing and classifying matter. Students explore the similarities and differences between elements, compounds, and mixtures and construct an appropriate classification scheme for particulatelevel representations of matter. Constructing a Particulate-Level Conception of Physical and Chemical Changes
The activity Change You Can Believe In27 is the first of two activities, both available as cited through the Target Inquiry Web site, that address the concepts of physical and chemical changes. This activity uses cards that illustrate particulate-level examples of physical and chemical changes. Figure 1 is a sample
Instruments and Data Collection
In determining the effectiveness of the activities in bringing about conceptual understanding, a published conceptual chemistry instrument, Particulate Nature of Matter (ParNoMA), was used.29 The instrument is a 20-question, multiplechoice test specifically focusing on students’ concepts at the particulate level related to phases of matter and phase changes. Each question addresses an aspect of the particulate behavior of matter, with distracters being directly related to common misconceptions. The authors of the instrument report 100% validity of the appropriate correct responses when examined by several of their colleagues as well as establishing the internal consistency of the instrument when administered to an introductory college chemistry section, N = 72, Cronbach’s α = 0.78. Students in this study were given the instrument both as a pretest and posttest in order to measure any changes in their conceptual framework. Student scores were reported as a percent of the number of questions they correctly answered out of 20. After obtaining parental consent and student assent according to the permissions granted by the Human Research Review Committee at Grand Valley State University, the pretest was administered to students during the first few days of the course. Students experienced the treatment curriculum during the third through fifth weeks of the course, and the posttest was then administered in a similar fashion during the ninth week, at the end of the marking period. The significant gap in time between the pretest, the treatment, and the posttest limits any test−retest bias. On the basis of the data from this instrument, structured interviews were conducted with five students during the second semester of the course, 4 months after the treatment and 3 months after the posttest, to probe specific concepts. The significant time lapse from the treatment was intended with the hope that the knowledge structures of the participants revealed
Figure 1. Sample activity card from Change You Can Believe In depicting the reaction of Mg(s) with HCl(aq) at the particulate level.
card, representing the single replacement reaction between magnesium metal and a hydrochloric acid solution. Students were not given information about what substances or processes were represented by each card. This was intentional, so as to prevent students from falling back on their macroscopic understandings and experiences to describe particulate-level situations. Students consider the cards with only their prior knowledge as a basis and categorize the cards as either physical or chemical changes. The student guides were constructed in such a way that led to discussion and debate between students. This process, guided by the instructor, allowed students to modify and clarify their particulate-level understanding of physical and chemical changes. Constructing a Symbolic and Macroscopic Conception of Physical and Chemical Changes
The Only Thing Constant in Life Is Change28 was the second activity intended to address the concepts of physical and chemical changes. Students performed actual macroscopic examples of the processes represented by the physical and 194
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questions on this survey have not been established as reliable measures of individual concepts. Thus, probing individual questions for further information about student understanding was not pursued. The data were collected from two different sections of the course. The authors wished to consider both data sets together, so the appropriateness of consolidation was considered first. Statistical analyses were conducted on student gains between pre- and posttest (posttest minus pretest). An Anderson− Darling test for normality was performed on each section using student gains. The test, which is optimal for small samples, showed that results from both periods, 3rd hour with p = 0.0755, and 4th hour with p = 0.349, could be considered normally distributed. As shown in Table 2, mean student pre- and posttest scores for each class do appear different. A test for equivalence was
in the interviews reflected their long-term understandings. Following an analysis of student gains on the ParNoMA, five students from both class periods were selected as potential participants in the interview based on the gains they experienced. One participant experienced no gain (0%) in his ParNoMA score, three students experienced moderate gains (15−20%), and one experienced large gains (50%). The protocol began with participants being presented with a clear liquid (water) boiling on a hot plate. The interview protocol did not describe the substance as water to avoid any prior knowledge bias of water’s behavior. The beaker contained water, though, for practical purposes. A small plate of glass was placed above the boiling liquid and condensation collected on the glass. Students were then provided with a pictorial representation of the situation that included several call-outs, or zoomed-in views, of the situation (Figure 2). The three call-
Table 2. Means and Standard Deviations for ParNoMA Scores by Class Period Pretest Scores, % Mean
SD
Mean
SD
third Period (26) fourth Period (28)
40.58 34.82
14.92 15.30
43.65 44.46
20.13 23.43
carried out to determine whether a priori differences existed between the two different class periods. The analysis of the ParNoMA pretest scores was done using two, one-tailed t-tests as prescribed by Lewis and Lewis.30 Results showed that the two groups could not be considered statistically equivalent to each other. The differences between these two populations may lie in which students get scheduled in each hour. The complexity of the high school scheduling process often allows for honors or elective classes to only be offered during certain hours. This often results in specific populations of students unintentionally remaining grouped together in other classes. This phenomenon may be at the root of the difference. Considering each section individually, a paired samples t-test was used to explore differences in student pre- and posttest scores. As summarized in Table 3, students in 3rd hour did not
Figure 2. Diagram used during interviews for participants to illustrate their particulate-level understanding of phenomena depicted: Water boiling in a beaker, evaporating, and then condensing on a glass plate.
outs referred to particulate behaviors within the beaker, between the beaker and the glass, and at the surface of the glass. Students were told that the substance in the beaker consisted of a compound comprising two elements, A and B. They were provided with small, blue triangles that represented atoms of element A and yellow squares that represented atoms of element B. The instructor constructed a particulate-level representation of the compound, consisting of one of each atom. The participants were then asked to construct and describe what they believed the particulate-level behavior of the substance would be in each of the call-outs. The instructor recorded video of the students modeling their ideas, including audio of their descriptions. The protocol also asked students to describe the changes the substance experienced and to identify them as physical or chemical changes.
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Posttest Scores, %
Class Period (N)
Table 3. Student Gains by Percent: Paired Samples t-Test Class Period (N) 3rd Period (26) 4th Period (28)
Mean Difference
SD
3.07
13.42
9.64
18.75
95% CI [2.34, 8.50] [2.37, 16.91]
F Values
p Values (TwoTailed)
1.17
0.253
2.72
0.011
show a significant improvement in score, while 4th hour results did show a statistically significant improvement, p = 0.011. The standardized effect size index (Cohen’s d) for 4th hour was 0.51, indicating that the intervention produced a medium effect. A power analysis using G*Power 3.1.2 revealed that the sample size for each period was too small to detect a small effect. This is important in drawing inferences from 3rd hour results. Figure 3 further illustrates student gains, showing the pretest and posttest means and 95% confidence intervals for 3rd and 4th hour results individually. This graph illustrates that both classes achieved similar results on the posttest, despite 4th hour students starting with a much lower mean pretest score. The statistically significant difference between pre- and posttest ParNoMA means for 4th hour warranted further
RESULTS AND DISCUSSION
ParNoMA Results
Statistical analyses using SPSS software were conducted to determine whether any changes in student scores, reported as percentages, between pre- and posttest occurred. While itemized responses for each question were obtained, individual 195
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and the instructor of the course. Thus, these results do not provide direct evidence for the novel curriculum over a traditional model, nor do they speak to the effectiveness of the curriculum in another setting. These results do, however, show that the novel curriculum had a positive effect on student conceptions regarding the particulate nature of matter as it pertains to phases of matter and changes in matter for students in the 4th hour class in our setting. Structured Interview Results and Discussion
The researcher attempted to obtain as much of a representative sample of the study population as possible through the selection of participants with diverse conceptions about the particulate nature of matter. Table 4 represents the participants’ pre- and posttest scores on the ParNoMA. Table 4. ParNoMA Results for Interview Participants ParNoMA Score
Figure 3. Student pretest and posttest mean scores (%) and 95% confidence intervals on the ParNoMA, broken down by class period.
considerations. A Pearson correlation between pre- and posttest scores showed a significant moderate positive correlation, 0.601, p = 0.001. This relationship suggests that participants who performed well on the pretest also performed well on the posttest. This result shows some relationship between a participant’s prior knowledge and their resulting knowledge after the described treatment. A second Pearson correlation between student pretest scores and student normalized gains [(post − pre)/(100% − pre)] on the ParNoMA showed no significant relationship, 0.036, p = 0.854. This suggests that the amount of conceptual gain, as evidenced by the normalized gain on the ParNoMA, was not dependent on the participant’s pretest score, independent of the absolute magnitude of the gain. Thus, students with a strong prior knowledge, while performing at a higher level on the posttest, did not demonstrate a greater gain in knowledge than students with weak prior knowledge. While the observed gains on the ParNoMA may seem meager, one must consider them within the broader view of the students’ educational experience. Prior to these students beginning this course, they had a well-established conceptual framework for how to describe and classify matter. To modify any one piece of a student’s misconception about matter, several steps must take place. Students must be presented with a situation that runs counter to their current framework. They must then be allowed an avenue to explore and make sense of the new information and formulate a new, correct conception. Such modification does not guarantee a correct conception, as the student may establish a new, yet still incorrect, conception that incorporates the dissonant situation.24 If one takes this snapshot of the Piagetian learning process and expands it to all of the concepts that fall into description and classification of matter, the cognitive load on the student becomes immense. Furthermore, students are not likely to have had any effective, appropriate instruction in particulate-level behaviors prior to their experience in this course.31 As a pilot study without a control group, the data describe the effectiveness of the curriculum as it pertains to the sample
Participant (pseudonym)
Pretest Score, %
Posttest Score, %
Nate Emily Kyle Ryan Allison
20 25 35 40 45
35 45 50 40 95
Audio and video recordings of participant responses were collected. Analysis and coding of the data focused on connecting participant responses to either correct conceptions or to previously identified misconceptions. The video coding software HyperRESEARCH32 was used to organize video clips and look for patterns. Representation of States of Matter at the Particulate Level
The substance in the beaker and the condensate on the glass should have each been identified and represented as a liquid. Correct representations included particles placed in close proximity to each other, but still allowing for freedom for particle movement. The liquid should have also lacked any sort of organized structure. With each of the five participants providing either a correct or incorrect construction for the two locations, 7 of the 10 models were deemed correct. Several examples of correct participant descriptions are given below. “It’s in the liquid form so it’d be close but still have enough room to move around.” (Allison)
“In here it’s going to be more of a consistently or evenly spread out liquid.” (Emily)
The three incorrect participant descriptions either involved an incorrect identification of the phase of matter that was observed or a description that did not clearly demonstrate that the participant understood liquid behavior on the particulate level. The substance between the beaker and the glass plate should have been correctly identified as a gas. Correct descriptions needed to include the fact that the particles were spaced significantly further apart than those of the liquid. Correct participant models frequently accomplished this by using fewer particles. Of the five potential participant responses, four were identified as correct. The only participant response that was 196
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marked incorrect did not clearly distinguish between the particle spacing of the liquid and the gas.
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CHANGES AT THE MACROSCOPIC LEVEL
Participants were asked to describe the macroscopic process of the substance boiling (which was set up in front of them) as a physical or chemical change. Four of the five participants correctly identified the process as a physical change. Appropriate justifications for such a response included recognizing that simple phase changes were occurring. “Physical, because it’s changing from a liquid to a gas and then back to a liquid”
Representation of Changes at the Particulate Level
Each participant’s model gave insight into how he or she thought the process he or she was observing at the macroscopic level affected the connectivity of particles. In representing the change that occurs between the heated liquid in the beaker and the space above the liquid, all participants chose to break the substance apart into its elements, which is incorrect and one of the hallmarks of this particular misconception. Interestingly, four of the five participants cited the heating process as the cause of the decomposition of the compound. “They undergo a chemical reaction because it’s heated.”
(Kyle)
“I think it would be a physical change because it’s going from a liquid to a gas to a liquid again so it’s the physical properties of the substance.” (Allison)
(Nate)
Such a response was in conflict with the participants’ particulate models and appeared to cause some cognitive dissonance for most of the participants. “A physical change because...well...maybe a chemical change because it’s being heated...so...well...actually I think it would be a physical change because it’s just water evaporating it looks like.”
“They break down because of the heat and it makes the atoms go faster and they break their bonds.” (Kyle)
“They boil, which breaks the bonds to make them a gas.” (Ryan)
(Nate)
All of the participants then oppositely showed the atoms recombining to form the original compound when they cooled and condensed on the glass. In each case, the elements were combined such that they were identical to those on the beaker. “Then the glass cools down the substance and they form back together”
Through their hesitant responses and body language, participants seemed to recognize that their descriptions of the changes on the macroscopic and particulate levels should have matched, although none of them explicitly made that statement. In summary, participants generally produced correct descriptions of liquids and gases at the particulate level. Participants could also clearly distinguish between chemical and physical changes at the particulate level. When asked to identify the macroscopic process as a physical or chemical change, all of the participants seemed to recognize that their macroscopic and particulate descriptions should have matched. Thus, it seems the piece that the participants were missing was the difference in strength between a chemical bond and intermolecular forces. The implications of this misunderstanding are far-reaching in an introductory chemistry course, as much of the traditional curriculum involves processes in an aqueous solution. The differentiation between the dissolution of a substance and any chemical reactions it may participate in while in solution requires a mental separation of processes involving intermolecular forces and processes that involve the breaking and forming of chemical bonds. Further consideration about how to appropriately establish a correct understanding regarding this conception is necessary. Furthermore, tools to assess the student conceptions involved in the distinction would need to be developed so that curricula could be evaluated appropriately.
(Kyle)
Thus, participants seemed to recognize that the substance on the glass and the substance in the beaker were identical. Identification of Changes at the Particulate Level
Participants were also asked to describe each of the changes as physical or chemical and provide a rationale for their decisions. All participants decomposed the substance in the transition to the gas phase and then reformed it on the glass surface. Thus, all participant diagrams represented chemical changes. Four of the five participants correctly identified and described their model as a chemical change taking place. Participant responses were identified as correct if they referenced bonds being broken and formed or if they referenced the formation of new substances. “Chemical change because there’s a different substance formed.”
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(Nate)
“Chemical, because the bonds broke.”
CONCLUSIONS Both the qualitative and quantitative results of this study provide support for the positive effect of the novel curriculum on developing students’ conceptual understanding of chemistry. As a pilot study without a control group, the data describe the effectiveness of the treatment curriculum as it pertains to the selected population and the instructor of the course. These results are not intended to prove superiority of the novel curriculum over other models, but merely to demonstrate its ability to positively affect student conceptions. As previously mentioned, the uncontrollable aspects of the high school
(Kyle)
“It’d be a chemical change because it’s breaking up the compound into two different things.” (Allison)
Participants seem to have a clear understanding of how physical and chemical changes differ on the particulate level, even though their conception of what actually occurred with the particles was incorrect. 197
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(11) Gabel, D. J. Chem. Educ. 1999, 4, 548−553. (12) Harrison, A. G.; Treagust, D. F. Sci. Educ. 1996, 5, 509−534. (13) Harrison, A. G.; Treagust, D. F. Sci. Educ. 2000, 3, 352−381. (14) Griffiths, A.; Preston, K. J. Res. Sci. Teach. 1992, 6, 611−628. (15) Stains, M.; Talanquer, V. Int. J. Sci. Educ. 2007, 5, 643−661. (16) Garnett, P. J.; Garnett, P. J.; Hackling, M. W. Stud. Sci. Educ. 1995, 25, 69−95. (17) Boz, Y. J. Sci. Educ. Technol. 2006, 2, 203−213. (18) Ahtee, M.; Varjola, I. Int. J. Sci. Educ. 1998, 3, 305−316. (19) Hewson, M. G.; Hewson, P. W. J. Res. Sci. Teach. 1983, 8, 731− 744. (20) Gabel, D. Educ. Quim. 2000, 2, 236−243. (21) DeBoer, G. E. A History of Ideas in Science Education: Implications for Practice; Teachers College Press: New York, 1991. (22) Bodner, G. M. J. Chem. Educ. 1986, 10, 873−878. (23) Harrison, A. G.; Treagust, D. F. Sch. Sci. Math. 1998, 8, 420− 429. (24) Posner, G. J.; Strike, K. A.; Hewson, P. W.; Gertzog, W. A. Sci. Educ. 1982, 2, 211−227. (25) Shadish, W.; Cook, T.; Campbell, D. Experimental and QuasiExperimental Designs for Generalized Causal Inference; HoughtonMifflin Company: Boston, MA, 2002. (26) Eizenga, D. Putting the World in a Box. Target Inquiry Teaching Materials. http://www.gvsu.edu/targetinquiry (accessed Nov 2011). (27) Bridle, C. Change You Can Believe In. Target Inquiry Teaching Materials. http://www.gvsu.edu/targetinquiry (accessed Nov 2011). (28) Bridle, C. The Only Thing Constant in Life Is Change. Target Inquiry Teaching Materials. http://www.gvsu.edu/targetinquiry (accessed Nov 2011). (29) Yezierski, E. J.; Birk, J. P. J. Chem. Educ. 2006, 6, 954−960. (30) Lewis, S.; Lewis, J. J. Chem. Educ. 2005, 9, 1408−1412. (31) Montes, L. D.; Rockley, M. G. J. Chem. Educ. 2002, 2, 244−247. (32) HyperRESEARCH Home Page. http://www.researchware. com/products/hyperresearch.html (accessed Nov 2011). (33) Simmons, P. E.; Emory, A.; Carter, T.; Coker, T.; Finnegan, B.; Crockett, D.; Richardson, L.; Yager, R.; Craven, J.; Tillotson, J.; Brunkhorst, H.; Twiest, M.; Hossain, K.; Gallagher, J.; Duggan-Haas, D.; Parker, J.; Cajas, F.; Alshannag, Q.; McGlamery, S.; Krockover, J.; Adams, P.; Spector, B.; LaPorta, T.; James, B.; Rearden, K.; Labuda, K. J. Res. Sci. Teach. 1999, 8, 930−954. (34) Roehrig, G. H.; Luft, J. A. J. Chem. Educ. 2004, 10, 1510−1516. (35) Roehrig, G.; Garrow, S. Int. J. Sci. Educ. 2007, 14, 1789−1811.
schedule may have contributed to the differences between the two sections. The scope of this study was to determine the effectiveness of the curriculum and not necessarily how the curriculum functioned within specific student populations. Understanding the specific differences between the two sections in this study may provide insight into how the curriculum could be modified to be more effective for specific student populations. Thus, further research into the effect of the curriculum on different student populations is warranted. The results of this study provide evidence for the effectiveness of the curriculum within a specific population. Further evidence would be required to make inferences about the performance of the curriculum in comparison to other curricula and in other school settings. First, a stronger argument for the novel curriculum could be made if it were shown more effective in concept building than a traditional model. This would require implementing the curriculum described here while simultaneously teaching a more traditional curriculum to an equivalent student population. However, providing instruction that may be inferior for the purpose of an experimental control may raise ethical concerns surrounding the teaching and learning beliefs of the instructor. Second, while the researchers expect minimal variation among different student groups, how an instructor implements the curriculum has been previously shown to significantly influence the potency of the curriculum.33−35 As such, an exploration of how both different student populations and different instructors affect outcomes due to the curriculum could provide support for the broader use of the curriculum and others designed around similar frameworks.
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AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected].
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ACKNOWLEDGMENTS We wish to thank the faculty and students of Grand Valley State University’s Target Inquiry Program for their input and collaboration in this effort. We are grateful for the willing participation of the students of Grandville High School. This material is based upon research and professional development supported by the National Science Foundation (ESI-0553215) and the Target Inquiry Program at Grand Valley State University. 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 Grand Valley State University.
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