Investigation of the Influence of a Writing-to-Learn Assignment on

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Investigation of the Influence of a Writing-to-Learn Assignment on Student Understanding of Polymer Properties Solaire A. Finkenstaedt-Quinn,† Audrey S. Halim,† Timothy G. Chambers,‡ Alena Moon,† R. S. Goldman,‡ Anne Ruggles Gere,§ and Ginger V. Shultz*,† †

Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States § Sweetland Center for Writing, University of Michigan, Ann Arbor, Michigan 48109, United States ‡

S Supporting Information *

ABSTRACT: We conducted a study to examine how a writing-tolearn assignment influenced student learning of polymer behavior. In particular, we examined the role of specific content and a rhetorical framework as well as a structured writing process including peer review and revision. The student-generated writing was analyzed via a content-directed rubric. Students’ conceptual understanding of stress−strain behavior was gauged via a multitiered assessment. Finally, interviews were conducted to probe students’ experiences during the writing process. Results indicate that the writing-to-learn assignment was effective in promoting understanding of stress−strain properties, but that further support is needed to help students connect polymer microscopic properties to macroscopic behavior. Specifically, the content requirements and rhetorical framework guided what students included in their writing. Peer review and revision provided students with further opportunities to engage and learn the material. KEYWORDS: Chemical Education Research, Polymer Chemistry, Writing, Collaborative/Cooperative Learning, Materials Science, Physical Properties, Atomic Properties/Structure, Second-Year Undergraduate FEATURE: Chemical Education Research

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molecules but are inherently more complex.8,11 This is further complicated when students consider the microscopic and macroscopic properties of bulk materials. Polymer chemistry bridges small molecules (monomers) and macromolecules (a polymer chain or network), extending to materials we use every day. Examining chemical systems simultaneously through these levels can lead to better student understanding.12 However, supporting teaching and learning in this area requires specific instructional materials.8,13 Writing-to-Learn (WTL) is a promising approach for teaching and learning polymer chemistry because its primary focus is supporting deep conceptual learning.14,15 Conceptual understanding is not universally defined in the literature. For the purposes of the study, we define conceptual understanding as knowledge of phenomena that is more than procedural knowledge, connects to other ideas and knowledge, and is transferrable to new situations.16 Conceptual learning requires restructuring existing knowledge, which is key in the study of polymers where students must rethink concepts to which they

olymers are highly versatile materials found throughout the world.1−3 This ubiquity is evidenced in the chemistry job market, where an estimated 50 percent of chemists hold a job that incorporates polymer science, spanning multiple areas of chemistry including adhesives, agriculture, alternative energy, biotechnology, nanotechnology, and medicine.1,4,5 Although pervasive, relatively little attention has been paid to polymers in education.6−8 While some universities offer polymer specializations for chemistry majors, most students only experience snapshots of polymer chemistry within traditional undergraduate chemistry courses.8 For these reasons, the American Chemical Society recently called for more emphasis on polymers throughout the chemistry curriculum.8 Polymer chemistry is highly interdisciplinary and could be introduced in any undergraduate chemistry course.9 Polymers are also an important component in disciplines outside of chemistry, including chemical engineering, materials science, and polymer science.7 Because of the various possible entry points to polymer chemistry students’ educational experiences with this topic are quite heterogeneous. Additionally, introducing polymer chemistry in the curriculum is challenging. Most students struggle to understand structure−property relationships in small molecules which is exacerbated when students are confronted with more complex systems.10 The structure−property relationships for macromolecules are not only distinctly different from small © XXXX American Chemical Society and Division of Chemical Education, Inc.

Special Issue: Polymer Concepts across the Curriculum Received: May 29, 2017 Revised: August 18, 2017

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have already been introduced.17 Writing supports this process as it involves reflective thinking and decision making when the writer rereads and revises their ideas.18 The ways in which writing promotes learning depends on both the type of writing activity and the context in which it is employed.15 WTL offers clear advantages for teaching and learning of polymer chemistry, yet very few assignments have been reported.19,20 Writing-to-Learn, as we define it, is based around a scenario designed to elicit students’ writing about key concepts in the role of an authority. Students first write about the concepts in response to the scenario then undergo the process of peer review and revision. Well-known examples of Writing-to-Learn include the Science Writing Heuristic and the Calibrated Peer Review system.21,22 What distinguishes our work from other investigations of writing in chemistry is the explicit emphasis on conceptual learning and the extension of the writing process to include both peer review and revision. This incorporates a social element into the writing process whereby students revisit their own work and revise based on peer feedback and insights from reading peers’ work. The primary learning objective of this WTL assignment was for students to connect the microscopic properties of polymer chains (average molecular weight, crosslinking, chain length) with their macroscopic behaviors (elastic/ reversible versus plastic/irreversible deformation). Herein, we describe a study aimed at understanding how a writing assignment influences student understanding of polymer chemistry. The study was framed by two research questions: 1. How do particular features of a writing assignment contribute to students’ conceptual understanding of the relationship between polymer structure and its properties? 2. How does the sociocultural aspect of the WTL process guide students’ understanding of polymer chemistry?

were quantified using a rubric generated by the research team. Quantitative analysis of students’ conceptual question responses were used to compare the learning gains of students under two conditions: students who participated in the polymer WTL and students who participated in a guided group discussion. Quantitative analysis of student writing was used to examine whether peer review and revision contributed to improvements in students’ conceptual understanding. Setting and Participants

This work was performed at a midwestern university in a lowerlevel Materials Science Engineering (MSE) course during two separate semesters. The course consisted of lecture and recitation sections with coursework including traditional problem sets, biweekly reflective writing, and WTL assignments. The prerequisite was either general chemistry or introductory organic chemistry. The textbook for the course was “Materials Science and Engineering” by Callister and Rethwisch.27 The participants consisted of 60 students who ranged from sophomores to seniors as well as one graduate student auditing the course. The students were primarily affiliated with the College of Engineering, over half with intended majors in Biomedical Engineering and Chemical Engineering. There were 15 female students, 13 students were non-U.S. born, and six were first generation. The engineering undergraduate students had prior training in technical writing in a prerequisite course. We received consent from all 60 students to use their survey responses and writing, 36 of whom completed the polymer writing assignment. Three students were recruited for audio-recorded interviews using availability sampling.28 They were invited to participate in interviews via e-mail and in-class announcements. We obtained IRB approval to collect student data, distribute surveys at the beginning and end of the course, and interview students.

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Writing-To-Learn Assignment

THEORETICAL FRAMEWORK As conceptualized in this implementation, WTL is grounded in sociocultural theory. According to Vygotsky, writing is unique in its capacity to embody thoughts and ideas through language, facilitating internalization or “inner speech”.23,24 In writing to a problem, students interact with social variables and negotiate meaning as they use shared symbols (i.e., written language) to communicate their understanding. Sociocultural theory informs the development of these writing assignments by making explicit social variables for students to interact with as they produce a written response. The assignment provides students with an identity, an audience, problem stakeholders, disciplinary expectations, and conceptual tools (i.e., graphs, research papers). Following the first draft, students engage in a reciprocal peer review process to enhance the results via social activity.25 This entire process (planning, writing, peer review, and revision) facilitates the internalization defined by Vygotsky as learning.26

Assignment Design. The WTL assignments focused on aspects of course content known to be conceptually challenging for students.11,29 Each WTL assignment was made up of a written response to a prompt, anonymous open response peer review performed by the students and revision of their original draft. Students did not score one another’s writing. The WTL assignment discussed here covered polymer mechanical properties and stress−strain behavior. Students were given the role of a volunteer in a social service program who needed to explain the implications of recycling on polymer structure to their supervisor, who hopes to convince donors that recycled plastic can be used to make backpacks for impoverished school children (Box 1). The prompt explicitly described key content learning goals and required students to read a research article by Pattanakul et al., which served as a data source for the stress− strain curve they were asked to create (Box 1).30 Note that MLA refers to Modern Language Association and is the citation style we requested students to use. Implementation. The WTL assignment was implemented during two semesters. The polymer-focused WTL assignment was the last of three assigned, taking place toward the end of the semester. Students had 1 week to write their initial response and half a week for both peer review and revision, respectively. Students received scores based on completion, with a cursory check to verify that they had attempted to address all the criteria, for both the initial and revised drafts. Points for peer review were awarded based entirely on completion. Additional support for students was provided by two peer tutors who had previously taken the course. The tutors were trained to help

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METHODS The purpose of this study is to understand the role of WTL in student learning about polymer chemistry. This study was performed using a convergent parallel mixed-methods approach in which both qualitative and quantitative data were collected to develop a more complete understanding.26 Qualitative data sources included student-generated text and semistructured interviews, which were analyzed to understand the ways in which writing contributed to learning. Quantitative data came from two sources: students’ responses to conceptual questions and the students’ written responses to the writing prompts, which B

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associated with the assignment they had not completed. In this way, the instructor accounted for time on task and created an opportunity for students to engage in a comparable manner with the particular material.

Box 1. Recycled HDPE for backpacks

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OBJECTIVE Over the summer you begin volunteering for a South Africa based social service organization, which is working to improve living conditions in impoverished rural areas using an environmentally conscious approach. In the area where you are working, waste management is a particularly low priority and the organization is hoping to design school bags for local children using HD polyethylene recycled from milk bottles. This strategy should mitigate waste management, while also providing a much-needed resource for children who travel a long way each day to school. Although your supervisor has a lot of experience with community service, they do not have a science background. In order to help your supervisor convince potential donors that recycling HDPE for use in the school bag is a viable idea, you need to read and summarize an article about the properties of recycled HDPE (Pattanakul, 1991). Your written summary should teach your supervisor about HDPE and the extent to which its mechanical properties will change after it is recycled so that they can decide whether it will be a serviceable material to use as the rigid frame of the bag. Estimate the stresses experienced by a typical backpack and use this estimate to decide whether the change in mechanical properties caused by recycling will significantly impact the performance of the backpacks. Include in your discussion a drawing of a proposed stress−strain curve that depicts HDPE before and after it is recycled. Be sure to describe what is happening both macroscopically and microscopically when external forces are applied. Items to keep in mind: • When we read your summary, we will play the role of an activist with minimal scientific background who is trying to understand why recycled plastics have different mechanicalproperties. • Your summary should summarize all important points from the paper but should focus onthe data contained in Table 2 (including a discussion of the yield strength, tensile strength, ductility, and modulus of elasticity). • Include and interpret your drawing of a stress strain curve of HDPE and describe how it would/could change for recycled HDPE. • External references are not required, but if they are used they should be cited using MLA format. • Since you are helping to persuade potential donors of the viability of this idea, you should take care to carefully edit and proofread your summary. • This should be a summary of between 350 and 500 words.

Assessment

An external measure was developed to assess student gains in conceptual understanding and was administered in class at the beginning and end of the semester. Students received participation points based on completion of the assessment rather than answering correctly. The assessment questions pertinent to the concepts covered in this writing assignment consisted of two three-tiered questions, where the first tier is a multiple choice question (Supporting Information, External Assessment), the second a short answer response explaining the reasoning behind their answer, and a third where students rank how confident they are in their answers.31−33 Analysis of the short answer responses revealed that student explanations were too brief to distinguish if they had a poor understanding of the concepts or were using minimal effort because credit was participation-based. Thus, the short answer responses were omitted from analysis. Students’ average confidence in their responses, on a scale from 1 to 5, to the two stress−strain questions was used. In the first semester, students indicated their confidence after answering both multiple choice questions and in the second semester after each question. The first question was developed by the research team, drawing from the textbook, to specifically target student’s understanding of tensile strength and percent elongation in the context of polymers. The second was drawn from a previously developed assessment and touched upon the yield strength of metals.29 Student assessment responses were only used in analysis if both pre- and postquestions were completed (N = 25 for writing, N = 10 for nonwriting). A McNemar test was used to evaluate differences in the number of students who answered the multiple-choice questions correctly between the pre- and postassessments. McNemar is used in lieu of a Chi-square or Fischer exact test when participant results are paired, as is the case in comparing pre- and postdata.34 For this and analysis of the writing (described below), statistical analysis was performed using the software package Stata. Writing Analysis

The writing was analyzed using a rubric derived from the peer review categories provided to the students. Key items, concepts, or approaches that were important to each category were identified. For each category, criteria were developed on a five-point scale by the researchers and content experts from materials science (elaborated rubrics provided in the Supporting Information, Table S1). For example, in criterion 4 students were expected to provide stress−strain curves pre- and postrecycling with the key characteristics appropriately placed and shapes indicative of a polymer. The group discussed what elements were important and iteratively developed the rubric to improve reliability by applying it to selected student responses and analyzing the scoring outcomes. For students who completed all steps of the WTL assignment, the initial and revised drafts were collected and analyzed (N = 36). Each student response was scored by at least two members of the research team who then came to an agreement on a single score.

students approach the writing assignments and learn content. Throughout the semester, tutors were available to facilitate peer review and answer both content and writing questions regarding the WTL assignments. Implementation was slightly different between the semesters. Participating students completed different numbers of peer reviews in each semester; in the first students reviewed the work of one peer and in the second they reviewed three. Additionally, in the second semester students were split into two groups; one group did the polymer WTL assignment and the other did a WTL assignment focused on metal corrosion. After completion of the respective assignments, during their recitation sections, each group participated in an expanded discussion of the topic

Reflective Interview

A semistructured reflective interview protocol was designed based on protocols previously reported for analysis of writing development.35 Modifications were made to emphasize the role C

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For criterion 2, the literature summary30 was evaluated primarily on students’ descriptions of tensile strength, modulus of elasticity, and percent elongation (see the Supporting Information, Definitions) because those are the primary elements considered in the context of the influence of stress on polymers. Additional secondary elements such as chain length or average molecular weight, melt flow index, and impact strength were included in the scoring. In both drafts, students tended to focus on the primary elements but left out the others, suggesting that the students did not recognize the secondary elements as important (Table 1; p = 0.0102, effect size = 0.4). Criterion 3 addressed the ability of students to interpret how changes to tensile strength, modulus of elasticity, and percent elongation relate to the functionality of the polymer. This criterion allowed us to determine how well students understood the implications of these properties on the physical behavior of the material. Students performed the best on this criterion, showing the highest initial score in addition to statistically significant gains after revision (Table 1; p = 0.0141, effect size = 0.54). Thus, they demonstrated a basic understanding of the meaning of the mechanical properties of interest and were able to discuss how recycling changes the polymer properties. Student stress−strain curves were analyzed (criterion 4) for the key features of a curve with a shape indicative of polymers and how the curve of HDPE changed upon recycling (by applying the data presented in the Pattanakul paper).30 We were additionally able to determine if students could assign macroscopic behaviors to the pertinent features on the stress−strain curve. For example, the ultimate tensile strength is the highest point of stress on the curve. For metals the curve typically peaks once and then decreases whereas for polymers the stress may again increase just before rupture (point C on Figure 1). Of the students who included graphs in their initial draft, many either (1) incorrectly presented the ultimate tensile strength or the modulus of elasticity or (2) created a metal stress−strain curve (Table S2, Student Writing Scores). Peer review and revision led to improvement of the stress−strain curves in all these areas (Table 1, p < 0.001, effect size = 0.72 and Table S2, Student Writing Scores). Students struggled the most with connecting the microscopic properties with macroscopic behavior and applying them to a polymer as force is applied (criterion 5). The inability to visualize and thus articulate the physical changes is a known difficulty for students.37 Despite low scores following revision, there were substantial gains in this area (Table 1, p = 0.0032, effect size = 0.69).

of writing in learning. Each interview took approximately 1 h and occurred after students had completed all stages of the assignment. The interview included questions such as “As you were writing, was there anything that came to the surface that you hadn’t thought of before?” and “In what ways did these comments help you make revisions to your draft?” to elucidate the WTL assignment’s impact on their learning. Three students were interviewed about the WTL assignment after submitting their final drafts. Student interviews were analyzed using an open coding approach.36 Audio recordings collected during the interviews were transcribed verbatim. Three members of the research team read each interview and identified repeating or salient themes regarding the student’ writing experience. Initial codes were created and revised after subsequent reading and discussion by the group.36 After multiple iterations three primary themes were identified: (1) interaction with the content, (2) decisions based on the rhetorical framework, and (3) guidance from sociocultural influences.

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RESULTS The interviews, writing, and external assessment were all analyzed to investigate how writing assisted in building content knowledge. Analysis of the writing samples demonstrated the extent to which students were able to incorporate and communicate their content knowledge before and after the peer review and revision processes. The external assessment served as an indicator of both students’ level of understanding and their confidence thereof. The interviews were analyzed to elucidate features of the prompt and WTL process that played a role in student learning and development of specific content knowledge. Writing Analysis

The writing was analyzed using a scoring rubric (Table S1) developed from the peer review rubric (Supporting Information), which mirrored the required content in the writing prompt (Box 1). Criterion 1 focused on the readability for a nonscientific audience. From a rhetorical standpoint, asking students to write for a nonexpert audience without the use of “textbook” jargon may reveal students’ own misconceptions and limited understanding. Student writing was determined to be more understandable to a nonscientific audience (Table 1) after revision (p < 0.001, effect size = 0.83). While most students succeeded in translating the terminology into their own words, they did not extend this to describing their graphs or how the process of recycling changed the polymer, which is supported by the low average scores (2.7 after revision) (Table 1). Table 1. Writing Scoring Criteria Analysis Results

Expert Ranking Mean Scoresa Criteria 1. Would this summary be understandable to a person with a minimal scientific background? 2. Does the summary accurately summarize the paper? 3. Does the writing make a coherent argument for why or why not recycled HPDE could be used to make backpacks? 4. Is a stress strain curve of the HDPE before and after it is recycled included? Are the graphs scientifically sound and the key features present? 5. Does the summary describe what is happening both macroscopically and microscopically when external forces are applied? a

Initial Draft (Std Dev)

Revised Draft (Std Dev)

t-Test Values (Degrees of Freedom = 12)

Effect Sizeb

1.5 ± 1.5

2.7 ± 1.3

5.21c

0.83

2.1 ± 1.0 3.2 ± 0.94

2.4 ± 0.77 3.6 ± 0.55

2.71d 2.58d

0.40 0.54

1.8 ± 1.6

2.8 ± 1.2

4.58c

0.72

1.1 ± 1.1

1.8 ± 1.1

e

0.69

3.17

N = 36 bCohen’s d. cp ≤ 0.05. dp ≤ 0.01. ep ≤ 0.001. D

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(Supporting Information). Interviewees described two major interactions with the content covered by the assignment: (1) application of previous knowledge to new situations and (2) in-depth thinking about concepts. Students pointed out that they were applying concepts they had learned previously in the course to a new situation. For example, students called upon stress−strain concepts encountered in the context of metals and applied that knowledge to a new material: We learned it during the previous chapter [Mechanical Properties of Metals] and it also helped us during this writing. Students indicated that they thought about the concepts in nuanced ways. All three participants pointed to microscopic and macroscopic changes in the polymer as a challenging aspect of the writing, where they needed to think about a concept at a deeper level than they had previously: You have to include necking as a macroscopic and then the alignment of the polymer fibers as the microscopic, to really understand what happens during failure or when external forces are applied. That’s why I included that stuff. This deeper thinking was also observed in a comment one student made regarding making choices about the shape of their stress−strain curves: The new stuff was coming up with sets of curves. Like I said, “How do I know what the curve looks like when it’s 10% embrittled?” That was something new. The above comments show that in responding to the content objectives of the assignment students experienced that content in new ways, consistent with our definition of conceptual understanding. The WTL assignment included a rhetorical framework, an aspect that is absent from many traditional science writing assignments. The assignment is framed around an authentic context: Can recycled milk bottles be used to make backpacks? By being in the role of expert, students are given autonomy in deciding what information was important to include in their summary and argument. Crafting an argument for an audience with minimal scientific background influenced the decisions of two of the interviewees regarding how concepts were presented. Specifically, it led to choices about the level and complexity of detail required for sufficient explanation: I might start really simple. Stating that HDPE is a polymer and then saying what a polymer is, because I’m not going to make any assumptions about the supervisor. It also influenced the choices students made about what information to include when making an effective argument; they needed to identify which mechanical properties were important for the functionality of the polymer in the specific application: With this elongation, it will not impact the properties of the backpack. The assignment also presents the students with two openended tasks: (1) creating a stress−strain curve and (2) making an estimate with data they identified in an authentic source.30 Extending what they had learned in class to the open-ended problems required decision making that all the interviewees

Figure 1. This representative figure displays a typical polymer stress− strain curve. As stress is applied to the polymer it first reaches the elastic limit (point A). Further stress brings the polymer to the ultimate tensile strength point (point B), and continued stress eventually causes the polymer to rupture (point C).

External Assessment

The external assessment measured student gains in conceptual understanding and confidence between the beginning and the end of the term. Comparing pre/post scores, for both questions, the McNemar test showed a statistically significant increase in the number of students who answered correctly for the polymer writing group but no significant difference in the nonpolymer writing group (Table 2). Because of small sample size, the polymer writing and nonpolymer writing groups could not be compared. More students were able to apply their understanding of polymer properties to identify the polymer with greatest tensile strength and percent elongation. Likewise, more students were able to connect their understanding of yield strength to deformation and tensile strength in the second question. Both groups of students showed statistically significant gains in confidence with large effect sizes (Table S3), thus gains in confidence could not be attributed solely to the writing. Interview Analysis

Three students were interviewed to provide additional insight into how the assignment prompt and WTL process (beginning from reading the prompt to submitting their revised draft) directed the formation of conceptual knowledge. Two of the students showed improvement between drafts, whereas the third had incorporated much of the desired material in the initial draft and thus had little room for improvement (See the Supporting Information for individual scores and exemplars to contextualize the comments, Table S3). Three themes emerged from the analysis: (1) how the content foci in the prompt guided learning, (2) how the rhetorical and interactive aspects of the prompt influenced student decisions, and (3) how the WTL process guided learning. Comments related to each theme were present in all the interviews. Specific content foci, important for understanding polymer properties in an application context, were incorporated into the writing prompt (Box 1) and peer review rubric

Table 2. External Assessment Results for Students Who Answered Correctly Students Who Did the Polymer WTLa

Students Who Answered Correctly Content Question Polymer stress−strain curve Metal yield strength a

Pre 12 3

Post 19 11

McNemar’s χ2 d

4.45 6.40d

Students Who Did Not Do the Polymer WTLb

Effect Sizec

Pre

Post

McNemar’s χ2

Effect Sizec

0.53 0.51

3 1

5 3

0.67 1.00

0.27 0.58

N = 25. bN = 10. cCohen’s d. dp ≤ 0.05. E

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students to apply content knowledge and provided them with feedback about their relative understanding of the material. Particular features of the assignment appeared to contribute to students’ conceptual understanding of polymer properties. The content objectives of the assignment guided students’ learning and their considerations about which mechanical properties are important to the application. One such example is the requirement for students to draw their own stress−strain curves, known to be conceptually difficult for students.11,29 All data sources indicated that the assignment resulted in an increased understanding of how mechanical properties translated into the distinct features of stress−strain curves (Table 1). While students had some difficulty distinguishing between metal and polymer stress−strain curves, after peer review and revision the number of students providing stress−strain curves with features indicative of polymers increased (Table S2). Students’ writing suggested that they struggled to interpret the microscopic and macroscopic structural changes that correspond to polymers experiencing stress or strain, as exhibited by their low scores on criterion 5 (Table 1). One possible explanation could be that the students still held compartmentalized knowledge and as a result were unable to map between different representations of the same phenomenon at different scales. Despite the low scores, the statistically significant gain (effect size = 0.69) between the initial and revised drafts (Table 1) indicate that the WTL process is an effective mode for increasing student understanding of the topic. To increase the assignment’s effectiveness, further guidance may be required to facilitate this type of student learning. This may mean simply being more explicit in the assignment about what is expected in the microscopic to macroscopic discussion or incorporating more time during the class connecting the two. Of the rhetorical features incorporated into the assignment, consideration of audience, in particular crafting an argument for a supervisor and potential donors, appeared to be an important aspect for guiding student writing. Generating a coherent argument for the use of recycled HDPE in making backpacks showed the greatest gain in the writing (Table 1, criterion 4). Additionally, the choices students made with regard to content were highly influenced by those features. They described making decisions about what was important to include when developing a persuasive argument about the viability of using recycled HDPE. The WTL process, which spans the initial planning to submission of the revised draft, also appeared to play an important role in student learning. The act of preparing to write and thinking about how to present and describe the material was beneficial. Peer review and revision led to significant improvement on all the criteria used in the writing analysis. All criteria, except students’ ability to summarize the results of the paper they read, showed gains between drafts with medium effect sizes. In the areas where students did make revisions, such as improving their stress−strain curves, the interviews indicated that peer review was the primary factor that led to these changes. The majority of students’ revisions appeared to arise from peer review feedback, as indicated by both writing analysis as well as the interviews. We believe this could stem from a systemic misunderstanding of what revision is, consistent with prior research that indicates that students typically feel that their initial submission is a polished product and do not recognize how to do revisions.39 This suggests that the products of student revision may not fully reflect changes in students’ content knowledge, part of which could be attributed to reading the writing of others,40 which merits further investigation.

found challenging. The different ways students approached decision-making is exemplified by how two interviewees approached creating stress−strain curves. Similar to work done by Drummond and Selvaratnam,38 one student recognized that there was missing information, but did not think about how to address the gap: The most difficult part for me is the stress−strain curve. Tensile strength is provided but I have to make up the yield point. It’s just kind of a randomized decision. The second extended their thinking to consider how other properties covered in class would impact the shape of the stress− strain curve: We weren’t really shown any examples of what happens when you embrittle a plastic, which could make it so that this doesn’t have that slope that comes down under. Collectively, the exemplar quotes above indicate that the rhetorical framework led students to make explicit decisions about how to craft their explanations, what information was pertinent to the context, and how to apply existing knowledge to new situations. The sociocultural process students underwent in completing the WTL assignment appeared to bolster learning by providing different viewpoints and space for reflection, with students engaging in both peer review and revision. The peer review served two functions for the students: confirmation that they had written about certain concepts correctly and a starting point for developing areas of partial understanding. Students started off the peer review process by reading one another’s responses, allowing them to evaluate their own work: ...reading another person’s paper helps. That’s where you start your process. You compare what you did, to them. By receiving feedback, students gained other perspectives on their work. Two out of the three interviewees found that peer reviews affirmed that they had successfully covered the material: In this situation, it made me feel like I touched all the details, but they didn’t I felt like, I did touch all the details that were asked for. I confirmed I had done a good job. Two also mentioned that the peer review feedback led them to make changes in their own papers: This guy is knowledgeable about this part, so he gave me some advice on which part I should cover to describe the microstructure. Both providing and receiving feedback allowed the students to view the same material with a different lens. Interviews revealed that when students made modest revisions to their writing, consistent with the degree of gains seen between drafts in analysis of student writing samples (Table 1), it was primarily in response to peer review feedback. One student mentioned making changes, but not substantial ones: I added a quick explanation of these, what a stress-strain response is and I can’t think of anything else to say, because I thought I did explain the features of the plot. Students only appeared to make changes if problems had been explicitly mentioned in the peer reviews they received.

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DISCUSSION

Overall, students developed a better understanding of polymer mechanical properties and stress−strain curves. When developing an argument, students made decisions about the level of explanation required and the polymer characteristics most important for the proposed application. The WTL process led F

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Limitations

ORCID

The limitations to this study were present in both implementation of the writing assignment and in investigating its role in learning. The small size of the comparison group limited our ability to make statistical claims about the learning gains attributable to a WTL assignment as opposed to discussion in recitation. Specifically, students demonstrated difficulty with the microscopic-macroscopic connections and there was very little improvement observed following peer review. This may be attributed to inaccurately gauging the knowledge base of the students when designing the writing prompt. Analysis of student learning gains was also limited because the external assessment only included two content knowledge questions and we were unable to use the short answer responses. In part because of this limitation, the primary claims from this study are tied to the qualitative analysis of the writing and interviews.

Ginger V. Shultz: 0000-0002-7285-748X Notes

The authors declare no competing financial interest.

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REFERENCES

(1) Seymour, R. B. Polymers are Everywhere. J. Chem. Educ. 1988, 65 (4), 327−334. (2) Harris, F. W. Introduction to polymer chemistry. J. Chem. Educ. 1981, 58, 837. (3) Sherman, M. Easy demonstration of the visible spectrum using the Spectronic 20. J. Chem. Educ. 1987, 64, 627. (4) Polymer Chemistry, https://www.acs.org/content/acs/en/ careers/college-to-career/chemistry-careers/polymers.html (accessed August 2017). (5) ACS ChemCensus 2015; 2015; p 16. (6) Bigger, S. W.; Hodgson, S. C.; Scheirs, J.; Orbell, J. D. The Effects of Thermal Treatment on Common Polymers - A Response to the Need for Educational Experiments in Polymer Chemistry. Polym. Prepr., 1999, 40 (7) Hodgson, S. C.; Bigger, S. W. Studying Synthetic Polymers in the Undergraduate Curriculum; A Review of the Educational Literature. J. Chem. Educ. 2001, 78 (4), 555−556. (8) Wenzel, T.; McCoy, A. B.; Landis, C. R. An overview of the changes in the 2015 ACS guidelines for bachelor’s degree programs. J. Chem. Educ. 2015, 92 (6), 965−968. (9) Cavalli, G.; Hamerton, I.; Lygo-Baker, S. What are we going to do about a problem like polymer chemistry? Develop new methods of delivery to improve understanding of a demanding interdisciplinary topic. Chem. Educ. Res. Pract. 2015, 16, 293−301. (10) Cooper, M. M.; Corley, L. M.; Underwood, S. M. An Investigation of College Chemistry Students’ Understanding of Structure-Property Relationships. J. Res. Sci. Teach. 2013, 50 (6), 699−721. (11) Montfort, D.; Brown, S.; Pollock, D. An Investigation of Students’ Conceptual Understanding in Related Sophomore to Graduate-level Engineering and Mechanics Courses. Journal of Engineering Education 2009, 98 (2), 111−129. (12) Treagust, D.; Chittleborough, G.; Mamiala, T. The role of submicroscopic and symbolic representations in chemical explanations. International Journal of Science Education 2003, 25 (11), 1353−1368. (13) Gilbert, J. K.; Treagust, D. Introduction: Macro, Submicro and Symbolic Representations and the Relationship Between Them: Key Models in Chemical Education. In Multiple Representations in Chemical Education; Models and Modeling in Science Education, Vol. 4; Springer Netherlands: Dordrecht, The Netherlands, 2009; pp 1−8, DOI: 10.1007/978-1-4020-8872-8_1 (14) Reynolds, J. A.; Thaiss, W.; Katkin, W.; Thompson, R. J. Writing-to-Learn in undergraduate science education: a community based conceptually driven approach. CBE-Life Sciences Education 2012, 11 (1), 17−25. (15) Rivard, L. O. P. A review of writing to learn in science: implications for practice and research. J. Res. Sci. Teach. 1994, 31 (9), 969−983. (16) Margolis, E.; Laurence, S. Concepts and Cognitive Science; The MIT Press: Cambridge, MA, 1999. (17) Kuhn, D. Education for Thinking; Harvard University Press: Cambridge, MA, 2005. (18) Bereiter, C.; Scardamlia, M. The Psychology of Written Composition; Lawrence Erlbaum Associates, Inc.: Mahwah, NJ, 1987.

Using WTL, students can successfully develop conceptual understanding of topics that are known to be conceptually difficult.14,15 This study demonstrates that a structured writing assignment and sociocultural aspects of the writing process facilitate student learning. To mitigate student areas of difficulty, such as those exhibited by the microscopic to macroscopic discussions described herein, the content targeted in the prompt should be (1) within the students’ ability to master and write about and (2) guided with an appropriate level of detail in the expectations. In addition to targeted content, providing rhetorical aspects, such as specifying audience and purpose, are important as they direct the students to consider the content more carefully as they write about it. Further work could also explore the impact of WTL assignments on self-efficacy, specifically in groups that may struggle with the material. The benefits of peer review result both from students’ reviewing multiple peers’ writing and receiving feedback from multiple peers. This increases the likelihood that students’ will interact with a particular peer whose understanding of a concept differs from their own. This is consistent with Vygotsky’s Zone of Proximal Development, which is what a student has the potential to learn when educational support is provided.26 Students struggle to revise their own writing.39 Thus, revision should be scaffolded to guide students to use feedback provided by their peers as well as the normative information gleaned from reading the writing of others and to prompt individual reflection when they reread their own writing.

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available on the ACS Publications website at DOI: 10.1021/acs.jchemed.7b00363. Three pieces of the WTL assignment, the writing prompt, peer review rubric, and revision guidelines which were provided to the students; rubric used to score the writing, example student generated stress−strain curves, multiple choice external assessment questions with student confidence results, and the distribution of students relative to the writing scores (PDF, DOCX)

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ACKNOWLEDGMENTS

We thank the University of Michigan Third Century Initiative for funding. Acknowledgment is made to Jack Hu, Emily Rizzi, and Raymond Pugh for discussion related to the polymer content and writing analysis.

Implications for Practice

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AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. G

DOI: 10.1021/acs.jchemed.7b00363 J. Chem. Educ. XXXX, XXX, XXX−XXX

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DOI: 10.1021/acs.jchemed.7b00363 J. Chem. Educ. XXXX, XXX, XXX−XXX