The Next Generation Science Standards (NGSS Lead States, 2013) represent a shift in the way science is conceptualized, requiring modification to science instruction and teacher preparation (Windschitl & Stroupe, 2017). The NGSS present science in conjunction with engineering as a set of common ideas and practices. As a result, teachers and teacher educators must be equipped with the skills and knowledge associated with understanding, employing, and adapting engineering design as needed (Hynes, 2012), as well as the capability to facilitate students’ collaborative engagement in working toward providing solutions to design problems (Capobianco, DeLisi, & Radloff, 2018). Studies have indicated that science teachers have expressed uncertainty (Capobianco, 2011) and discomfort (M. C. Hsu, Purzer, & Cardella, 2011) with learning to teach science through engineering design. Consequently, widespread use of engineering design–based science instruction remains uncommon in undergraduate science courses for preservice teachers (Roseler, Paul, Felton, & Theisen, 2018).

Interestingly, using engineering design to teach science has been found to increase students’ science attitudes (Guzey, Moore, Harwell, & Moreno, 2016), problem-solving skills (Wendell & Lee, 2010), and science content performance (Bethke Wendell, & Rogers, 2013) across K–16 education and offers relevant and authentic contexts for science learning and engagement (Turner & Hoffman, 2018). More research is needed to understand how these findings translate across different contexts as science teachers, teacher educators, and university instructors continue to adopt engineering design–based science instruction in their classrooms. In this study, we investigate the impact of a life science design task on elementary preservice teachers’ knowledge and perceived relevancy of composting and modeling related to science and engineering design. The design task, focused on composting and mapped to the NGSS, is described in detail along with student outcomes.

The purpose of this study was to describe how a biology instructor used engineering design as a way to address new science education reform while promoting student science learning and relevancy. To this end, the instructor used a three-dimensional learning approach to develop the design task. Three-dimensional learning represents the integration of disciplinary core ideas (DCIs), science and engineering practices (SEPs), and crosscutting concepts (CCCs) and is designed to help students learn and reason about science phenomena and engineering solutions (Krajcik, 2015).

DCIs represent the big science ideas presented in a lesson or unit. In the composting design task profiled here, the DCIs relate to energy flow within ecosystems. SEPs represent “behaviors that scientists engage in as they investigate and build models and theories about the natural world and the key set of engineering practices that engineers use as they design and build models and systems” (NGSS Lead States, 2013). For the compost task, the SEPs included modeling, asking questions (science) and designing solutions to problems (engineering), and evaluating and communicating findings. CCCs are global concepts across different areas of science. The CCCs for the compost tasks included references to patterns; cause and effect; systems and system models; and scale, proportion, and quantity (NGSS Lead States, 2013).

The context of this study was a required, introductory biology content course for preservice elementary teachers (undergraduate elementary education majors) at a large, research-intensive, Midwest university. The course was designed to help the preservice teachers learn about biology through inquiry-based, collaborative, reflective, and metacognitive experiences (Akerson, Abd-El-Khalick, & Lederman, 2000). Through these experiences, the course focused on fostering preservice teachers’ understanding of core life science ideas including: ecosystems, energy flow, population ecology, photosynthesis, and cells and cellular respiration. It was comprised of one 1-hour large lecture and two 2-hour lab sessions per week. The current study describes the instructor’s first attempt at integrating a design experience in this respective course.

The larger unit of study was comprised of the following instructional activities: (a) a 10-week aquarium/terrarium “Ecosystem Project”; (b) a 4-week “Current Issues Project”; (c) four monthly “Reflexivity Assignments”; and (d) “Thinking Critically” exercises. For the Ecosystem Project, lab groups of four to five preservice teachers engaged with various SEPs toward developing a terrarium/aquarium ecosystem model, creating hypotheses, taking observations, recording and analyzing data, and forming and communicating their conclusions through midterm and final lab reports. The Ecosystem Project spanned the months of August through October and the Current Issues Project covered November and December (see Table 1).

For the Current Issues Project, the lab groups researched a current science issue and presented it to the class. The monthly Reflexivity Assignments were made up of five critical questions that preservice teachers reflected on: (a) what was important to learn and why; (b) how the curriculum connected with authentic science as performed by scientists; (c) how the curriculum connected with daily life; (d) what course activities they would use in their future classrooms, and why; and (e) how content and activities could be used to transform their home communities. The Thinking Critically exercises were 5- to 10-minute weekly discussion prompts emphasizing different socioscientific issues each week, such as global warming, “Indigenous” vs. “Western Modern” science, or the still ongoing Flint, Michigan, water crisis.

A total of 137 preservice teachers across eight lab sections (15–20 students per section) participated in the study. The demographic profile of the preservice teachers included the following: 90% female, 9% male, and 1% not preferring to answer. They were 92% Caucasian, 1% Asian, 1% Hawaiian or Pacific Islander, 1% Black or African American, and 4% multiethnic; 1% did not prefer to answer. The preservice teachers had little to no experience with engineering design–based science instruction.

Novel to this course was the Compost Design task, which was implemented as part of a larger unit on energy flow (i.e., cellular respiration and photosynthesis) and situated within a contemporary socioscientific issue. The preservice teachers were tasked with working collaboratively to explore and model the use of composting in an effort to help the citizens of Puerto Rico recover after the destruction caused by Hurricanes Irma and Maria.

The design brief read as follows: “Rather than dumping the materials into landfills or the ocean, the local government is interested in a more ecologically friendly solution: compost.” The constraints and criteria included: (a) the solution had to be repeatable, and (b) materials to be added were limited to those found in the affected area (see Figure 1 for more information about the design brief and context; see also Appendix A, available at ).

The learning objectives of this design task centered on understanding energy flow through an ecosystem, scientific modeling, and composting. The design brief asked the preservice teachers to complete the following: 1.Conduct online research to learn more about compost, what it is, and how it is made. 2.Use this research and the labs that we have already completed this semester, and develop a plan that will include: a labeled sketch of what the model compost pile in the 2-liter bottle looks like at the start of the process, a list of the kinds and quantities of materials that should be added to the compost, a description of how these materials should be arranged in the model, a description of the steps to be followed to provide the best conditions for the most rapid and complete decomposition, and answers to the reflection question.

The Compost Design task incorporated the use of 3D learning (National Research Council, 2012; see Table 2).

On the first day of the design task, preservice teachers in their lab groups were provided with the design brief. They learned about (a) the context of the task including the criteria and constraints, (b) space for the students to provide their compost models (sketches, recipes, and arrangement of materials), and (c) a short set of questions to answer in their lab groups about the purposes and processes of composting and modeling. They were then instructed to perform in-class online research in their lab groups to find five facts related to the process, conditions, and materials associated with composting, providing correctly formatted citations for where they found each fact.

During the second day, lab groups compiled their facts and worked on their models, making sure to address criteria and constraints. Groups used 2-liter bottles as a frame of reference for their plans and were asked to provide justifications for their plans based on their research and previous labs emphasizing energy flow through ecosystems (see Appendix A for model template, available at ). They were then asked to respond to the following questions: 1.What is the purpose of designing this model? How does the way that this model is used for this compost scenario compare with how other models have been used during this semester? 2.Did developing your plan for the model compost pile help you improve your understanding of biology topics such as cellular respiration, decomposition, trophic levels, or other course concepts? If so, please explain how.

On the final day, groups completed their proposed design solutions and submitted their sketches, plans, and responses to reflection questions about composting.

The preservice teachers completed pre- and postconcept assessments on the core biology ideas related to the task before and after completing the design experience (see Appendix B for full instrument, available at ). The content assessments were comprised of 15 multiple-choice questions that covered topics related to energy flow within ecosystems and composting including: decomposition, cellular respiration, aerobic and anaerobic reactions, bacteria, and organic matter. The assessment was developed, scaled, and validated by the researchers and course instructor following the process described in the Standards for Educational and Psychological Testing (American Educational Research Association, 1999). This included the use of Rasch analysis for validity and reliability (Boone & Scantlebury, 2006). One or more items were adapted from publicly available item banks such as the American Association for the Advancement of Science Assessment Project 2061 (DeBoer, 2005). Below is a sample question:

When considering the role of bacteria in compost, they can be best described as: a) consumers b) producers c) decomposers d) competitors Correct answer: decomposers

Students created sketches of their planned models and responded to key questions about the purpose and processes of composting and modeling. Students also completed one of their monthly reflexivity assignments (critical reflections) one week after the design task had ended.

Data analysis entailed paired, two-tailed t-testing of students pre- and postassessments (H. Hsu & Lachenbruch, 2014). Open coding (Saldaña, 2015) was utilized to analyze preservice teachers’ responses to composting questions and the reflexivity assignment, with emphasis placed on their understandings of composting and modeling and the relevancy of the design experience to these life science constructs.

Results yielded three trends. The preservice teachers demonstrated: (a) significant learning gains on science concept assessments, (b) knowledge about modeling, and (c) an informed perspective of the design task as personally relevant.

Paired t-testing of concept assessment scores showed significant gains in preservice teachers’ understanding of science content (p < .01) associated with the task. Mean scores had increased from the pre- to postassessments from 9.61 (SD = 2.18) to 10.98 (SD = 1.95). See Table 3.

Preservice teachers’ responses to key questions revealed their critical reflections about composting and modeling. Through their monthly reflexivity assignment, they reflected on (a) the use and role of modeling as part of the design brief and (b) the potential relevancy of the composting task. All provided quotes were extracted from final lab reports generated by the lab groups.

Responses to compost design brief questions indicated that the preservice teachers expressed two different ideas about the role of modeling in the design experience. The first idea was that modeling, in this case, was used to reinforce preservice teachers’ understanding of composting. For example, one group wrote that “the purpose of designing this model was to learn how to design a compost pile and to learn about the decomposition of materials” (lab group report, fall 2017). Here, the group members describe learning about compost design and decomposition, a DCI of the task.

The second idea was that modeling was an aspect of experimentation used to represent actual scientific phenomena, with over 50% of lab groups emphasizing modeling within this particular design context (i.e., Puerto Rico). For instance, one group stated how “the purpose of designing this model is to see a bigger process and concept in a smaller, more controlled way to learn” (lab group report, fall 2017). Here, the group emphasized the smaller, manageable scale of the model in relation to the actual phenomena. Another group described that “this model was designed to extrapolate an executable solution to the hurricane-induced tragedy and the ecological effects on Puerto Rico” (lab group report, fall 2017). In this example, the group connects modeling with solving the actual problem.

When asked, “Did developing your plan for the model compost pile help you improve your understanding of biology topics such as cellular respiration, decomposition, trophic levels, or other course concepts? If so, please explain how,” 75% of groups reported modeling helped them see how it works, why it is important, or how to design a compost pile. The remaining 25% of groups described how modeling helped them learn about what materials are important in designing compost piles (e.g., a mixture of layered green and brown material; mixture of macro and microorganisms).

For example, one group stated: “The model helped us understand decomposition because it demonstrated a real-life process and connected it to a real-world issue. We also had to research the levels of the compost pile, which helped us understand decomposition” (lab group report, fall 2017). In this example, the preservice teachers described having to engage in research to learn what science content and design knowledge (e.g., materials available in Puerto Rico) were necessary to complete the model, which they connected with its real-world application. Another group described how they “became more aware of what materials help the process of composting and how they help the process” (lab group report, fall 2017). Another lab group described the science concepts and terms learned in class, stating: “We had to figure out what order to put the decomposing materials through what we have learned in this class. We also know decomposition needs oxygen to respire to keep breaking down material” (lab group report, fall 2017).

The purpose of examining reflexivity question responses was to determine if and how preservice teachers responded to the design experience in relation to other course activities and content. Approximately half of the preservice teachers stated composting as: “important to know about,” “connected with their everyday lives,” “an activity they would use in their future classrooms,” and “as a way of changing their home communities.” All of these suggested it was personally relevant to them as citizens in their community, college students, and future teachers. For example, one preservice teacher wrote the following: I think the idea of engineering design and the focus on the impact of composting is important to know. It all ties into our ongoing talk about the ecosystem and the environment, which I think every college student should learn about. The importance of using engineering design to solve a problem is an essential skill for everyone to have.

Another preservice teacher stated the following: The compost pile lab is a great example of everyday science. Everyone has scraps that they throw out and believe that they are no longer in use. This is a great lab to show how scraps and dead leaves and other things can be used…to help out a community. Therefore, this lab was connected to anyone’s daily activities and was a great learning experience for me and hopefully for my future students.

In this response, the individual emphasized composting as relevant to everyday science, as well as its utility in helping improve communities. They also described intending to use this activity in their own future classrooms. A third preservice teacher described composting as transformative, stating: We spent a little bit of time talking about composting, which is a huge thing that can be done to help benefit my community. Starting a compost pile in my own community and encouraging others to do the same would help improve the recycling of organic materials and allow them to cycle back into the environment more efficiently.

In this example, the individual highlighted composting as an effective way to help with local sustainability and human impact.

Significant increases on content assessments emphasized that the preservice teachers learned science content through engaging in the compost design task. Although there was no control group, this finding was noteworthy because it pointed to the effectiveness of using engineering design to teach and learn science content (Bethke Wendell, & Rogers, 2013; Capobianco et al., 2018). It also suggested that, like inquiry-based instruction, engineering design–based science instruction may be an equitable and accessible method of science instruction (Braaten & Sheth, 2017). This also appeared to be the case from the perspective of the instructor. Although this was the first time he had implemented this design task in the course, the preservice teachers still exhibited learning gains and knowledge of the related SEPs following engagement in the task.

Hence, preservice teachers’ understanding of modeling was important when considering the use of three-dimensional learning and the NGSS (NGSS Lead States, 2013) in creating the compost task. This is because the development and implementation of the compost design task offered an opportunity for the preservice teachers to engage with and apply standards-based science content (DCIs), practices (modeling; SEPs), and CCCs within a real-world, authentic context. The preservice teachers in this study demonstrated adequate understandings of modeling following the design task. They were able to describe its purpose and how it helped them learn about composting within the given context of hurricane cleanup in Puerto Rico, reminiscent of outcomes of three-dimensional learning as described through standards and literature (Krajcik, 2015; NGSS Lead States, 2013).

Findings also suggested that the context of the design task (hurricane cleanup) offered a powerful hook, or entry point from which students could understand core science and engineering ideas and practices. Explicit attention to the context of the design task highlights the real-world, authentic nature of engineering design (Pahl & Beitz, 2013), as well as the impact of emphasizing both timely and national socioscientific events as a context for science learning (Zeidler, 2014). This trend was further supported by the preservice teachers’ reflexivity responses, in which they explicitly signified elements of the compost design task as important to them personally and in relation to their future teaching and civic action.

Engaging preservice teachers in design in the context of an undergraduate science course suggests that learning science through design is achievable. By framing an engineering design experience around the tenets of 3D learning and the context of a real-world problem, the university instructor in this study demonstrated the capacity to integrate authentic learning experiences that not only leveraged his current curriculum but, more important, also encouraged his students to learn key life science concepts, principles, and practices. Although the integration of design is still new to undergraduate science courses, the potential for incorporating design across courses and programs is limitless. This study profiled one such attempt and demonstrated the effectiveness of how integrating design in an undergraduate life science course can support student learning and engagement.