Building an Understanding of How Model-Based Inquiry Is

Jun 19, 2015 - teaching of science content. This connection influences model selection and instructional strategies, including model-based instruction...
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Article pubs.acs.org/jchemeduc

Building an Understanding of How Model-Based Inquiry Is Implemented in the High School Chemistry Classroom Katarina Dass, Michelle L. Head,* and Gregory T. Rushton Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw, Georgia 30144, United States S Supporting Information *

ABSTRACT: Modeling as a scientific practice in K−12 classrooms has received a wealth of attention in the U.S. and abroad due to the advent of revised national science education standards. The study described herein investigated how a group of high school chemistry teachers developed their understanding of the nature and function of models in the precollege classroom through participation in a yearlong professional development program designed using model-based inquiry (MBI) as a framework. Further, we sought to understand the factors that catalyzed or hindered the incorporation of this pedagogy into the participants’ classrooms. It was found that the program positively influenced the teachers’ understanding of modeling as a scientific practice and facilitated growth in navigating pedagogical and conceptual challenges towards implementing modeling practices in their classrooms. KEYWORDS: High School/Introductory Chemistry, Curriculum, Laboratory Instruction, Inquiry-Based/Discovery Learning, Constructivism, Professional Development, Chemical Education Research FEATURE: Chemical Education Research



INTRODUCTION Models have played a central role in chemistry instruction both in elucidating various chemistry phenomena and in tracing historical progressions about ideas such as atomic structure, bonding, and thermodynamics.1−5 Although we can observe chemical and physical processes at the macroscopic level, scientists have long used models to aid in describing the underlying atomic and molecular interactions that determine the system’s properties. In some classrooms outside of the United States, teachers have reported utilizing particulate-level models to aid in explaining how and why changes in matter take place, but have not described helping their students to do the same.6−10 In a recent search of this Journal for modeling in the high school classroom, several publications were found that discuss how students use of teacher-generated models to explain a variety of concepts.11−16 Some articles have also recently appeared with a discussion of how modeling practices are utilized in the AP Chemistry classroom.17−19 Only one article currently appears in this Journal that provides an example of a model-based inquiry activity.20 A recent Google Scholar search utilizing the keywords “model-based instruction” or “modeling” and “high school chemistry” resulted in no reports that discussed how high school chemistry teachers incorporated modeling practices into their classroom to learn chemistry content. Recent reform documents such as the current AP Chemistry Curriculum Framework21 and the K−12 Framework for Science Education22 advocate for students to make connections © XXXX American Chemical Society and Division of Chemical Education, Inc.

between the macroscopic and particulate levels of chemical and physical processes so that a more coherent and complete understanding of these phenomena can be developed. To accomplish such goals, chemistry teachers should be able to design experiences where students are given opportunities to elucidate underlying relationships by constructing and evaluating models. At the same time, teacher educators who design and deliver professional development (PD) for chemistry teachers must consider how pedagogical content knowledge (PCK) related to these practices is acquired. Outside of the U.S., it has been reported that there is a strong connection between a teacher’s understanding of the nature of models and the extent to which they are included in the teaching of science content. This connection influences model selection and instructional strategies, including model-based instruction.23 Not surprisingly, students’ understanding of models and their ability to engage in the act of modeling is largely influenced by their teachers’ abilities.24−26 The study described herein investigated how a group of high school chemistry teachers developed their understanding of the nature and function of models and how they incorporated modeling practices in the precollege classroom through participation in a yearlong PD program designed using MBI as a framework. Model-based inquiry (MBI) is an instructional method that relies on the central tenets of inquiry while calling on the students to construct, test, and revise models. Students would

A

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Table 1. Modes of Representing Models6 Mode

Definition

Concrete

Visual

Refers to a three-dimensional representation that may be presented on a different scale than the target Refers to a description of the system and the relationship among the components Refers to the use of symbols or formula to represent the components of the target Refers to a two-dimensional representation

Gestural

Refers to the use of body parts and their movement

Verbal Symbolic

Example Ball-and-stick models or atomic orbital models. This may include analogies such as the construction of a s’more to address stoichiometry or a simple written description describing he position of atoms relative to each other in a molecule. A mathematical equation to explain a relationship or a Lewis dot diagram to depict covalent bonding. Includes graphs, drawn diagrams of a laboratory setup or particulate representations, simulations/animations or wedge-dash drawing of a molecule. Positioning your body in a trigonal planar shape (hands together above head and feet spread apart) or acting out the transfer to electrons to form an ionic bond.

strategy to build student understanding, these findings are not surprising.28,29,34,35 Due to the unfamiliarity that many teachers have engaging students in the act of modeling, incorporating such a change may be met with challenges. Windschitl has discussed the challenges and constraints teachers have reported when attempting to implement constructivist reform pedagogies and categorized them into four domains of “dilemmas”: conceptual, pedagogical, cultural and political.36 The conceptual dilemma is related to the teachers’ understanding of the foundations of constructivism (i.e., the philosophical, psychological, or epistemological basis), while the pedagogical domain is associated with approaches taken toward curriculum design and learning experiences that accommodate the demands of constructivism. The cultural domain includes new classroom roles and expectations of the teacher and students during classroom interactions, and political domain describes relationships regarding the norms and routines of the school and larger educational community. Acknowledging these challenges and constraints and addressing them within the design of a PD program may allow for more successful implementation among participating teachers.

then use these models to develop evidence-based arguments that develop their understanding about a concept.6,27 Like other instructional approaches consistent with recent reform documents, model-based inquiry (MBI) leverages students’ innate curiosity about the natural world and does not require a particular student skill set or prior knowledge per se to be effective at achieving positive outcomes. The research questions that guided this study included: (1) How did the teachers’ conceptions of the modes and roles of models change over time? (2) What kinds of inhibitors did the teachers report as influencing their ability to implement modeling in their classroom? (3) What perceived catalysts did the teachers experience when first implementing modeling in their classroom? Collectively, these findings may inform how the design of future professional development and the content in chemistry teacher education courses may be further improved to influence the incorporation of the modeling practices into high school chemistry classrooms.





BACKGROUND Although the explicit presence of models and modeling is new to U.S. national science standards, this has been a topic of discussion that has appeared extensively in the international science education literature. A number of international research papers have explored teachers’ perspectives of models, the nature of models, and their function in the teaching of chemistry content.3,7,9,28−30 The term “model” has been described in a variety of ways. To guide this study, Gilbert’s definition of a model was used: “a system of objects, symbols, and relationships representing another system (called the target) in a different medium.”31 Models are expressed through one of five modes, which are summarized in Table 1, and were used as an analytical framework through which teachers’ responses could be understood. Justi and Gilbert studied a group of teachers in Brazil and the United Kingdom and found that they generally agreed that modeling was valuable in their practice and recognized the perceived benefits of it in science classrooms. Cited benefits included improved student engagement, facilitation of more structured explanations, improved formative assessment, students’ ability to visualize particulate interactions, and promotion of learning about the nature of science.7 Other researchers have found that teachers can identify the value of models as pedagogical tools, but emphasize them less as a scientific practice that students can use to understand the nature of science.7,32,33 Given that most chemistry teachers likely have limited experiences using modeling as a pedagogical

PROFESSIONAL DEVELOPMENT FRAMEWORK FOR MODELING The PD model created for Target Inquiry37−39 has been reviewed, and features that led to its effectiveness were considered when designing the PD utilized in this study. These features include the importance of utilizing findings from related theory and research, along with offering ample opportunity for the participants of the PD to engage in activities that allow them time to construct personal knowledge and beliefs about the new pedagogy. The current PD approach was also developed from recommendations that were made in related literature for modeling instruction7,29 and included the following features with regards to influencing teachers’ use of models and modeling: 1. Content knowledge about the nature and use of models must be addressed. 2. Teachers must be directly involved in the practice of modeling during training sessions. 3. Characteristics of curricular and teaching models must be discussed and reflected upon. 4. Discussions about how models and modeling may be used to guide discussions and contribute to meaningful learning in the classroom should be discussed frequently. 5. Teachers’ repertoires of model-based activities must be expanded and improved over time. B

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Following this review process, the teacher then designs a secondary exploration, which may be a subsequent section of the experimental procedure, simulation, or another demonstration to provide the student with an opportunity to apply and test the model they have created. The students then attempt to utilize the information that they gathered from their peers and the secondary exploration to further refine and revise their models. Finally, the students engage in a peer-review session of the secondary models developed in the class to receive further feedback. Since this is a cyclical framework, it may repeat depending on the learning outcomes and time constraints. The project leadership, consisting of two chemistry education faculty members at the sponsoring institution and one master chemistry teacher from a local high school, was aware of the potential difficulties with both understanding and enacting model-based inquiry with the teachers, given their previous lack of experience. As a means to address these challenges, three design features of the PD were explicitly imposed. First, the summer workshop began with topics that were conceptually less difficult and already incorporated some aspect of modeling in the conventional instructional approaches. Gas laws, for example, are often taught algorithmically but with particulate-level drawings to support the calculations, so we chose to begin the instruction with lessons around this topic. By starting at such an entry point, the teachers appeared to respond positively toward the additional modeling practices that were advocated by the PD design. Second, the teachers were frequently placed in the “student role” and asked to think through the ideas from a ‘student perspective’. This approach was done to offer a low-stakes environment in which the teachers could voice concerns and questions, or clarify conceptual or computational ambiguities in their knowledge by assuming a “nonteacher” persona. We have found that teachers are often uncomfortable asking questions in the presence of their peers for fear of appearing incompetent. By assuming a student role, they could voice these anxieties under the guise of what a student might ask. Lastly, a typical activity designed by the leadership team included enough aspects of a conventional lesson to show teachers that although modeling practices were unfamiliar, they did not need a whole new set of materials to enact the curriculum. Information about this professional development opportunity was shared with the local teachers by the science supervisors. A total of 31 local chemistry teachers at various levels of experience applied to participate in the summer workshop. Preference was given to teachers with less than three years of teaching experience (N = 9) and to teachers who held a “broad-field” science teaching certificate, but whose primary teaching load was chemistry (N = 15). This resulted in a total of 19 teachers selected to participate in the professional development. All teachers had a current teaching load that included on-level or honors chemistry, and three teachers also had AP Chemistry as part of their schedule. Few teachers reported holding leadership positions in their schools (N = 2) or having earned advanced degrees (Masters of Education or Education Specialist) (N = 4). Further demographics of the teachers and their participation can be found in Supporting Information Tables S2 and S3. The selected teachers were compensated with both a small stipend and continuing education credits. Although the demographics of the group displayed some diversity in teaching experience, the preworkshop survey outcomes indicated a limited exposure to modeling

6. Teachers should be required to reflect on the implementation of the model-based activities in their classroom during academic year training sessions. 7. Teachers should be given time to better understand their students’ conceptions of models and their abilities related to modeling. To ensure that the teachers developed a strong conceptual understanding of the scientific practice of modeling, a common instructional cycle was repeated for the activities that were carried out during the PD. MBI was used as the conceptual framework27 to guide this structure, and as a scaffold for the teachers to design their own classroom activities when their comfort and competence with modeling improved. Figure 1

Figure 1. Model-based inquiry from the perspective of the teacher.

depicts MBI in the context of what the teacher may do to foster this inquiry pedagogy. At each stage of this inquiry cycle, the instructor considers what activity or prompt will be given to the students and how collaborative learning will be facilitated. This framework incorporates many of the aspects of Justi and Gilbert’s Model of Modeling,9 but shifts it from a studentcentered process to one that is teacher-centered. That is, a framework for how a teacher may develop a classroom activity to guide students through the process proposed by Justi and Gilbert is presented. The cycle begins as the students explore a phenomenon at the macroscopic level; this could be the first part of an experimental procedure or class demonstration. From here the students are prompted to construct a model to explain an aspect of what was observed. The level of experience students have with the modeling practice will govern the amount of detail contained in the modeling prompt. Just as with scientific models proposed by scientists, other classmates would then critique the initial models to identify the strengths and limitations of those created. At this point the teacher should consider how the collaboration with other groups would be structured. C

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as a scientific practice. As such, they were all considered novices at implementing related practices in their classrooms. The PD consisted of a total of 56 h spread between a week long summer workshop and three academic year sessions, and is summarized in Table 2. A detailed schedule can be found in

Table 3. Changing Conception of Models

Themes

Table 2. Timeline of Professional Development and Survey Administration

Modes of Models

Professional Development Meetings (N)

Coded Sources

Data Collection Events (N) Pre-Workshop Survey (17)

Summer Workshop −40 h (19)

Roles Of Models

Post-Workshop Survey (17) First Term Survey (14) November Workshop −8 h (13)

February Workshop −4 h (11) March Workshop −4 h (9)

Second Term 1 Survey (11) Second Term 2 Survey (9) Focus Group Interview (11)

Supporting Information Table S1. Each day of the summer workshop was split into two main sessions: a morning session focused primarily on exposing the teachers to MBI activities and further development of content knowledge, and an afternoon session focused on unpacking the lessons by reflecting on the phases of the MBI cycle. Also during the afternoon, time was given to discuss how MBI could be used to achieve differentiation and academic language development in the chemistry classroom. The group then met during the academic year, where instruction focused on further design of MBI lessons and classroom implementation.

PreWorkshop

PostWorkshop

First Term

Categories

N = 18

N = 17

N = 14

Concrete Visual Verbal Gestural Symbolic Tool for visualizing/explaining concepts Depicts general representation of a chemical process Student roles in construction Modification/revision Scope and limitations Multimodal description of one chemical process

13 10 3 2 1 6

7 11 2 2 2 10

3 8 2 1 0 10

4

8

12

0 0 0 0

0 0 0 0

5 2 2 2

To answer the second and third research questions, survey questions related to each area and the focus group interviews were open-coded to initially reveal the common themes among the data. Due to the similarities among the open codes and Windschitl’s dilemmas for the implementation of reform-based teaching practices,36 each open code was then mapped on to one of the four dilemmas. A complete list of the open codes and their relationship to Windschitl’s dilemmas is provided in Supporting Information Table S4. The focus group interviews and related survey questions (found in the Supporting Information) were coded in their entirety by a second coder to establish interrater reliability. An average Cohen’s κ value of 0.863 was calculated, which is considered almost perfect agreement.41 Among the results in Table 5, the pedagogical domain was further categorized to differentiate among the catalysts of the modeling approach. The results aided in providing recommendations for implementation of modeling in high school classrooms.



RESEARCH METHODS A phenomenological research paradigm was used to guide the research design and the methods used for data analysis.40 The primary purpose of this work was to understand the essence of a shared experience in learning about and engaging in modelbased inquiry practices. The data collection methods included a series of online surveys and a focus group interview, which were conducted following participants’ consent to participate in the research study. The timeline for implementation is noted in Table 2 and the questions for each data source have been included in the Supporting Information. To probe the first research question, participants were given the same recurring prompt, “What is your definition of models as it is related to the chemistry classroom?” during the Pre-, Post-, and First Term online surveys administered by the external evaluator. The timeline for implementation is shown in Table 2. Those responses from participants who consented to the research study were entered into NVivo (a qualitative analysis software program) and coded utilizing the modes of representations presented by Gilbert.6 A series of open codes was also generated to determine how the role of models in the chemistry classroom changed over the course of the PD. The number of participants responding to the survey (N) is reported Table 3. Inter-rater reliability was established using all established codes for 10 responses from each survey administration. The Cohen’s κ values are also reported in this table. To determine if there was a significant change in the participant’s definition of a model over time, a Chi-Square Test of Homogeneity was performed among the distributions presented in Table 3.



RESULTS AND DISCUSSION

High School Teachers Changing Definition of a Model

Over the course of the program, a change in the participants’ conception of a model was observed to shift from a description of the mode of a model, to how it is represented, to the roles models play in the classroom (Table 3). Although there was not a significant difference among the coding distribution between each time interval, there was an overall statistically significant change from the administration of the Pre-Workshop survey to the First Term survey (X2 (d.f. = 10) = 18.31, p < 0.01). Definitions in the Pre-Workshop Survey focused on the modes of representing models with the emphasis on concrete and visual representations. A representative comment from one participant stated, “I think of two types of models. The first is the traditional “ball and stick” models and/or molecular model kits: VSEPR shapes, water molecules, NaCl cube. The second type of model is a picture (or) drawing of what the person thinks is happening on a molecular level.” Following the summer workshop, responses in the PostWorkshop Survey revealed a shift from description about modes of representations of models to the inclusion of the role of a model in the classroom setting. Although participants D

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“The issue that I’m having is just trying to find the time with all the other standards that we’ve got to hit in Chemistry”

“Having the supplies necessary to do the modeling” Political and Cultural Monetary or Material Acquisition

Cultural

Political Classroom Management - Time Management

“It’s new to me. So if I put a question on a test, I already have something in mind that I’m looking for. Like, how am I going to evaluate it? I’m not really sure exactly” (A barrier that is foreseen when implementing modeling is) “Push back from students initially not being sure what I am asking for. I have honors students and they always want specifics of the requirements. When I leave things open-ended they get nervous but that also provides for an array of answers which is good” Pedagogical

Methods for Evaluating Models Classroom Management -Student Resistance

Suggestions for overcoming inhibitors Domain

“I think that’s kind of the beginning struggle is they’re getting new content and a new strategy at the same time.”

Typical Response E

Inhibitors

Table 4. Inhibitors towards Implementation

The inhibitors that emerged from the focus group interviews, once the teachers had about six months to enact modeling practices, are summarized in Table 4. The number of coded references does not appear in this table since the results reported are an amalgamation from responses of multiple participants during one focus group interview session. Although the teachers reported conceptual and pedagogical concerns, most could be captured within Windschitl’s political and cultural domains (those being perceived as governed by entities external to the teacher). These findings are consistent with other research on teacher enactment of reform-based practices.42−46 The challenges that the teachers faced did not relate to finding value in models or understanding of the modeling paradigm, but rather focused on how to influence existing classroom, school, and district norms with regards to the scientific practice and curriculum. Two constraints that the teachers identified when implementing the MBI practice in their classroom were coded as a pedagogical dilemma. These constraints included adaptation of new inquiry-based practices by the students and the lack of

Pedagogical and Conceptual

Perceived Inhibitors When Implementing MBI

Adaptation to new inquiry-based pedagogical practices

continued to express multiple modes of representing models, the more robust definitions relied less on specific examples and more on a general understanding of a model as a representation of a target and its applications, as exhibited by the quote below: “[A model is] any type of representation that will give the learner a better understanding of content or phenomenon.” Participants primarily identified the role of a model as a representation of a chemical process and as a flexible tool used for visualizing and explaining a concept, both largely teachercentered practices. The inclusion of the roles of models shows an increase in participant understanding of general aspects of models and modeling. Definitions in the First Term Survey demonstrate that, as the teachers begin to implement this pedagogy in their classroom, their definition continues to shift to now include the student role in modeling. This shift is exhibited by the sample quote: “Models are two fold in that one type may consist of use of a molecular model kit to construct particular molecules. The other is where students based on prior knowledge create a drawing of a chemical situation in regards to a hypothesis of what will take place. Then after conducting the experiment and drawing a conclusion they compare their hypothetical model to that of the results. If they are correct in their original model that is super and if not changes are made in it and explanations of what has transpired in the experiment are noted and explained.” This is the first time it was observed that the participants identified the importance of student model construction and revision of a model. To a small extent, but still noted, they begin to identify the scope and limitations of models used in the classroom, as well as using multiple forms of a model to convey an idea. This suggests a more complex understanding of the roles of models and their application as a tool for inquirybased learning. The results of Table 3 exhibit the development of a more sophisticated understanding of what a model is. Although the participants were given the same survey prompt, their responses shifted from describing a model as a tool to using modeling as an approach. This suggests a relationship between participants’ exposure to MBI-based PD and classroom implementation for recognizing the students’ role of using models in the classroom.

Begin modeling with content students are already familiar with and make adjustments as new material is incorporated. MBI is a practice it has to be embedded consistently throughout the curriculum. Modeling is a practice and therefore may not have a right or wrong answer. To evaluate this skill properly. a well-structured rubric needs to be established. Sharing and reflection are major elements of MBI, and therefore, to gain buy-in from the students, it must be implemented in its entirety. It is important to reward the process and not only the correct answer. Current standards (NGSS and AP) include the use of model-based instruction. Develop a curriculum that incorporates MBI to enhance and meet state and local standards. Rethink how activities already used in the classroom may be reworked to fit the MBI framework. Due to the limited number of resources that utilize MBI, it is important for practitioners to share their ideas and activities.

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to seek help from their peers. A change in classroom culture aided this teacher’s navigation of student resistance to result in successful implementation. One final challenge that was revealed early on during the teachers’ exposure to MBI was the need for materials or monetary acquisition to develop model-based lessons and to perform labs that would facilitate this style of learning. During the Post-Workshop Survey, six of 17 participants mentioned materials as a barrier they foresaw. However, by the Second Term 1 survey, only one of 11 participants expressed this need. This finding was further supported by the focus group interview, in which only one participant mentioned materials or financial support as an inhibitor for implementation. This does not represent a significant change among the teacher’s responses over time. Therefore, it is evident that the initial incorporation of common classroom equipment and portions of already developed lessons into the MBI framework aided in allowing the majority of the teachers to see the applicability of this practice to their own classroom. The PD also encouraged teachers to network and share resources related to MBI through an online platform, which may have further allowed them to feel as though they had the necessary access to adequate resources to initiate modeling practices in their classrooms. As the workshop progressed, both the teachers and the workshop leaders offered suggestions for how to better achieve the MBI practices in the classroom. These suggestions are outlined in Table 4. The teachers commented that the followup workshops were vital, allowing them to share ideas and classroom experiences on how best to overcome some of the obstacles that were described. This input, in conjunction with the results from Table 3, demonstrates that MBI PD should be accomplished through a series of meetings during the academic year to achieve a higher rate of implementation.

methods for evaluating models; both were regarded as concerns that arose from the teachers’ need to develop new materials to implement MBI. The teachers spoke in much depth about the struggle to find assessments that captured the skill and ways of thinking about models and the open-ended nature of the modeling practice. This issue did not appear to affect the teachers’ intent to pursue further development of model-based lessons, lending support to the idea that greater exposure to quality MBI lessons would aid in a greater degree of implementation. Both of the pedagogical concerns may be viewed as largely within the control of the teacher. Constraints related to classroom management, both with regard to time management and student resistance, emerged as themes from both the Postworkshop survey and the focus group interviews during the academic year follow up. The context in which time management was mentioned changed following a period of implementation. Initially, teachers raised concerns with the amount of time it would take students to develop, reflect, and revise models as well as time required planning activities or labs that utilize MBI. Following a period of implementation, time constraints were largely discussed from a perspective of needing to be able to meet all of the course standards while enacting modeling in the classroom. This PD experience took place prior to the adoption of the NGSS or the 2013 AP Chemistry Framework, which now require students to engage in this scientific practice. Therefore, teachers felt the need to prioritize the demands of the classroom to meet all the content standards over the desire to incorporate more modeling. Due to the influence that standards appeared to have had on classroom practices, this dilemma was categorized as mostly political. The idea that modeling practices could actually improve efficiency at addressing standards was not realized at first. As emphasized by Windschitl, “teachers may undergo profound changes in their beliefs about what counts as learning, what classroom activities should be valued, and what the role of the teacher is”, with constructivist reform.36 Therefore, teachers needed to evaluate their current practices and those presented by MBI to determine if the modeling practice, which may take longer but may result in a richer discourse, is more valuable than their current practices. During the initial stages of implementation, the teachers expressed this as a current, ongoing evaluation. Another constraint regarding classroom management that the teachers addressed was student resistance to the practice. Data collected during the focus group interview indicated a positive shift compared to responses during the early stages of the MBI-based PD. Teachers admitted that, although they sensed uncertainty from students during initial implementation, both students and teachers adjusted quickly (i.e., within weeks or months) through consistent practice. Several positive experiences with modeling, in conjunction with classroom management, were reported after initial implementation, as revealed by one participant’s narrative during the focus group interview: “... I just found out that they have come to a point of where they can kind of just control themselves as far as who needs help, who doesn’t need help. And I usually go over it one time with them. And I say this is my time to going (sic) over it with you. I said, ‘Hey it’s on you all.’ And they somehow tend tothat they got real good at working and trying to think through things.” In this case, model-based lessons appeared to enhance group communication and students’ recognition of when they needed

Perceived Catalysts When Implementing MBI

Although the teachers reported barriers to implementation, the focus group data suggested that there were seven central catalysts that encouraged participants to continue the practice and development of model-based instruction. Table 5 summarizes these findings. The outcome of the coding scheme described previously indicated that all catalysts could be classified within the pedagogical domain, and were found to describe distinct areas of teacher development. Even though the group of teachers varied in their years of experience, there was no observed difference between the cited catalysts among these teachers. A catalyst that the teachers discussed was how the MBI practice shifted the culture of the classroom from teachercentered to student-centered, and with it, resulted in improved student engagement. From the focus group data it was noted that participants’ attempts to incorporate the MBI pedagogy into a lesson plan achieved the intention to infuse exploration, self-expression, and reflection into their classrooms. The focus groups also indicated that the teachers recognized the importance of utilizing student-constructed models to identify misconceptions students had about various chemical processes. Teachers reported that students were becoming active learners, and tended to rely less on teacher instruction and work independently or within small group settings. This perceived benefit was classified as pedagogical knowledge because it demonstrated that the teachers were developing a student-centered classroom based on the principles of model-based inquiry. F

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I grouped the students based on their learning styles. So I’d have a poster on my wall with like, they’d do the VARK Questionnaire. And then I could easily go up there and pick like a V and an A and a R and put them in a group together. So I think it helps incorporating that when they’re modeling because maybe the visual kid gets it, but the auditory kid does not get it. And when the visual kid can show the auditory kid, then it brings everybody’s level up. So I really feel like that has helped in both understanding how to model and their being able to explain it and comprehend it. And it definitely paid off. Pedagogical

Assessment for Learning

The one thing I noticed was that whenever they draw a picture, they’re beginning to draw a picture first but it helps to find out where the misconceptions are.

This perceived benefit was also supported by the growth made in the types of activities that the teachers shared during the follow-up meetings. A second benefit that teachers reported was an increase in their own content knowledge. Participants discussed that moving through the MBI process as a student during the PD resulted in an improvement in understanding the nature and properties of particular chemical systems. Subsequently, some participants reported a higher self-efficacy in teaching the topics addressed by the PD. This was reflected in the choice of chemistry topics teachers used to develop lessons for initial MBI implementation. Overall, participants developed modelbased lessons that used topics that were scaffolded for them during the PD. However, some (N = 7) shared model-based lessons during the follow-up meetings that used new activities, independent from those to which they had been exposed. This suggests that the teachers were able to begin to apply the central MBI framework to other chemistry topics, and in a few cases even other subject areas, thereby demonstrating growth in the area of pedagogical content knowledge. Furthermore, one participant applied modeling to teaching a subject other than chemistry, anatomy, and physiology, suggesting that MBI could be an effective pedagogy for other science courses. Participants’ application of model-based instruction across a large scope of topics and subjects demonstrated the flexibility and relevance of the pedagogy. The final perceived catalyst related to the role that the teacher and student play in formative assessment. The initial modeling of a target system was reported to expose student misconceptions to the teacher. Therefore, MBI allowed teachers to spend more time on new content by quickly and efficiently revealing students’ misconceptions early on and provided a tool that helped correct those misconceptions by challenging discrepancies found in student models. As the students continually engaged in the modeling practice, it was also reported that they became more aware of their own learning. Upon completing the modeling process (by applying their initial models to a secondary exploration), the students were able to self-assess where they had gaps in their understanding. Collectively, these findings suggest that teachers first needed to understand the features of MBI and how to use it in their classrooms before they could navigate inhibitors that were external to their classroom. What appeared to be pertinent to the enactment of model-based inquiry in this project, however, was the familiarity with the concept and language associated with models and modeling. We then attempted to support a growth in expertise and comprehension by engaging in multiple instructional cycles involving various content-specific topics during the summer and academic year workshops. Once the teachers themselves were comfortable with incorporating modeling within their classrooms, they began introducing some of these ideas to their students slowly and over a period of time. We found that once the teachers became acclimated to the approach, enacting lessons that included modeling perspectives did not create additional obstacles for their students that had not been overcome previously. While most participants were able to reconcile their former pedagogical philosophies with a new constructivist model-based pedagogy, other participants did not. The overall decrease in participation and response rate may have occurred because those participants did not find value in the practice of MBI or may have felt that the inhibitors posed too much of a barrier to

A method for quickly assessing and correcting student misconceptions A strategy for students to recognize and correct their own misconceptions

Pedagogical and Conceptual Pedagogical

Pedagogical

Exemplary Response

In terms of concepts and so forth, it did allow me toI felt like I understood the concepts a little bit deeper, the knowledge part of it, gave me more confidence as it related to teaching the concepts. At least with the drawing some of them that have trouble expressing themselves (in writing) that can draw it and express themselves better, labeling and so forth, and they don’t contradict themselves. This is exemplified when one participant transcended chemistry applications and implemented MBI in another science discipline, anatomy and physiology. Pedagogical ContentKnowledge Pedagogical

Pedagogical and Cultural

Pedagogical Knowledge

Area of Gain Domain

Pedagogical and Cultural

Article

Shift from teachercentered to studentcentered instruction Shift from passive learners to active learners An increase in teacher content knowledge Increase in creativity within pedagogy Flexibility of modelbased pedagogy

Catalysts and Perceived Benefits

Table 5. Catalysts and Perceived Benefits towards Implementation

I just found out that they have come to a point of where they can kind of just control themselves as far as who needs help, who doesn’t need help. And I usually go over it one time with them. And I say this is my time to going over it with you. I said, "Hey it’s on you all." And they somehow tend tothat they got real good at working and trying to think through things. It was helpful to my kids, and even when I was thinking about it, because it made them express what they thought was going on. Like, it’s one thing to think you know what’s going on. But when you have to try to explain it, you really have to have, um, a grasp of the concepts.

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overcome. One participant stated, “It was helpful for me to see a deeper understanding of the content, but I don’t believe I would use these in my actual classroom.” This response may give insight in how to structure PD going forward.

infused to further understand how it affects student learning with regards to depth of conceptual understanding, the incorporation of argumentation discourse, and academic language acquisition.





IMPLICATIONS AND CONCLUSIONS The results of this study demonstrate that the findings align well with constructivist reform dilemmas as described by Windschitl,36 concluding that MBI may be considered a reformbased pedagogy and not just a scientific skill that should be introduced in the high school chemistry classroom. The PD design was successful at allowing the teachers to develop a better understanding of modes and roles of models. The findings also suggest that the PD was effective at addressing the conceptual and pedagogical dilemmas that teachers face when enacting modeling instruction. The analysis of the perceived constraints was devoid of how to implement modeling but rather focused on dilemmas that arose from implementation. Therefore, this implies that the cultural and political domains should be the focus of the academic year support for these teachers once they recognize the value of this scientific practice. The findings all reveal the importance of providing the followup academic year support, since it was able to provide the teachers with a forum to share ideas of how MBI looked in their classrooms and discuss the barriers that were encountered. For current teachers considering implementation of this practice, but who do not have access to such professional development, it is important to consider how to enact modeling gradually and through minor modifications. That is, it is not advisable to complete the full model-based inquiry cycle right from the beginning. A consideration of common challenges the group of teachers with whom we worked may provide insight into how to work around them to avoid similar experiences. As educators develop exemplary model-based inquiry activities, it is important to share them with the broader chemical education community due to lack of examples in the current literature. Overall, the perceived student development gains catalyzed the teachers’ persistence in developing an MBI approach in their classrooms. It became apparent that the cycle of implementation, discovery of perceived benefits, and continued implementation was essential to a sustainable culture of MBI in the classroom. We propose that an effective PD model should begin with the what, why, and how of model-based instruction to allow the teachers to overcome the constraints internal to their classrooms. Once they have evaluated the benefits of the practice, the academic year support should shift to focus on further navigating this cycle by understanding external constraints that fall in the political and cultural domains. Since these domains are governed by external entities and challenge the norms within the school, elements associated with teacher leadership (e.g., advocacy, self-efficacy, and identifying stakeholders) should be infused throughout the PD to allow the teachers to better navigate these barriers. The inclusion of this may have increased the overall number of participants who complete the entire program. Although the results and conclusions made are based on self-reported data, it provides an initial discussion of how modeling is to be adopted and practiced in U.S. Chemistry classrooms. As a result, the most important features of the professional development have been identified and serve to provide a narrower scope through which to focus further efforts related to the implementation of modeling in the classroom. Future studies will focus on collecting data from classrooms where this practice has been

ASSOCIATED CONTENT

S Supporting Information *

Supporting Information has been included to provide more information about the structure of the professional development and the teachers who participated in the program. Information has also been included to demonstrate in greater detail how the results were further analyzed. This material is available via the Internet at http://pubs.acs.org.



AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. Notes

The authors declare no competing financial interest.



ACKNOWLEDGMENTS The authors would like to thank all the participants in the Teacher QualityImproving Chemistry Education for All: An Exploration of Chemistry on the Particulate Level for their willingness to openly share experiences with this new practice. We also acknowledge the Georgia Department of Education Teacher Quality Higher Education Program for funding this work.



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