The Design, Field Testing, and Evaluation of a Contextual, Problem-Based Curriculum: Feedback Analysis from Mathematics Teachers on the Field Test Version of Connected Mathematics^®4

Abstract

For over forty years, each edition of the Connected Mathematics^® curriculum reflects the understanding that teaching and learning are not distinct—“what to teach” and “how to teach it” are inextricably linked. Each edition goes through iterative cycles of design, development, field testing, data feedback, and revision. Grounded in the theoretical and empirical curriculum design and enactment tensions that emerge in problem-based mathematics classrooms, this study reports on teachers’ perceived effectiveness of implementing and enacting the field test version of Connected Mathematics^®4. Analysis of the survey revealed that the problems in the field test version of the fourth edition promote student engagement and learning in mathematics, problem-solving, mathematical connections to real-life applications, and multiple solution strategies. We also discuss implications for how the curriculum design, development, and professional learning experiences involving teachers and their students help provide cohesive and effectively sequenced materials to support students and teachers in rich mathematical problem-solving experiences.

1. Introduction

Mathematics curriculum—the content, organization, sequencing, and methods of instruction—forms the foundation of mathematics education. As Ball and Cohen (1996) argued, the relationship between curriculum materials and teachers has often been underexamined in mathematics education. Curriculum materials are not effective in isolation; developers frequently assume that textbooks are static resources that can operate nearly independently of teacher input (Dow, 1991; Remillard, 2005). However, teachers play a central role as mediators between curriculum materials and student learning. Providing critical feedback that informs the ongoing development of these resources and regular communication between curriculum designers and teachers are essential to ensure materials are responsive to classroom realities (Ben-Peretz, 1990; Pepin, 2019; Stein & Kim, 2009). Thus, the quality and effectiveness of curriculum materials matter for improving mathematics teaching.

As research has consistently shown, the effectiveness of curriculum materials is deeply influenced by how teachers interact with, adapt, and modify them, which in turn affects student outcomes (Borko & Putnam, 1996; Cohen & Hill, 2000; Silver & Smith, 1996). Recent research has highlighted the importance of teacher feedback in adapting and improving curriculum materials during development. Teachers are not merely implementers of curriculum but active participants in the design process who offer essential insights on how materials can be adjusted to better meet classroom needs (Jones & Pepin, 2016; Remillard et al., 2009). Teachers rely heavily on textbooks and curriculum materials for the “what” and “how” of teaching mathematics (Robitaille & Travers, 1992), but they can use these materials in varied ways. These different approaches result in unique kinds of interactions between teachers and students, focusing on sequences of mathematics problems that may not necessarily resemble the interpretations and decisions made by the teacher in planning (Lloyd, 1999; Remillard, 2005). Stein and Kim (2009) emphasized that teacher engagement with curriculum materials directly shapes how these materials are enacted in the classroom. Teachers must “perceive and interpret existing resources, evaluate the constraints of the classroom setting, balance tradeoffs, and devise strategies—all in the pursuit of their instructional goals” (Remillard & Heck, 2014, p. 18). Thus, research and practice underscore the dynamic relationship between teachers and curriculum materials, suggesting that teachers are crucial in the development, use, and refinement of effective teacher resources.

Building on the literature that emphasizes the importance of the teacher–curriculum relationship, we explore the role of teacher input in the development of a new edition of a set of problem-based curriculum materials. We argue that involving teachers in the design process is crucial for generating materials that are both educative for teacher learning and effective in the classroom. Classroom materials must support teacher learning. As observed by Ball and Cohen, “[u]nlike frameworks, objectives, assessments, and other mechanisms that seek to guide curriculum, instructional materials are concrete and daily. They are the stuff of lessons and units, of what teachers and students do… Not only are curriculum materials well positioned to influence individual teachers’ work but, unlike many other innovations, textbooks are already ‘scaled up’ and part of the routine of schools. They have ‘reach’ in the system” (1996, p. 6). Curriculum materials can help teachers enhance their content knowledge and refine their teaching strategies (Brown, 2009; Davis & Krajcik, 2005). Teachers also need materials that are flexible enough to allow for adaptation, ensuring that diverse classroom contexts and student needs are addressed (Jones & Pepin, 2016; Remillard et al., 2009). These interactions between teachers and materials create a dynamic feedback loop that can lead to improved curriculum designs and more effective teaching practices (Remillard & Heck, 2014).

This paper examines how teacher feedback was integrated into the development of the field test version of the Connected Mathematics Project (CMP) middle grades Connected Mathematics^®4 (CMP4; Phillips et al., 2025a, 2025b, 2025c) curriculum. Through a survey of teachers who field-tested the materials, we explore how their feedback influenced the iterative process of curriculum design and enactment. This study addresses the often-overlooked need for curriculum materials to be extensively field-tested in diverse classroom settings using design research methodologies, coupled with sustained professional learning. By focusing on the teachers’ perceptions of both the design and classroom enactment of the materials, this work foregrounds the teacher–curriculum relationship and contributes to the growing body of research emphasizing the importance of teacher input in the development of effective educational resources and the improvement of student learning outcomes. These contributions are particularly significant for CMP, which evolves across editions by refining and building upon established foundations; incorporating field-based teacher insights is therefore essential to ensuring the curriculum remains relevant, effective, and responsive to classroom needs.

1.1. Conceptual Framework

As shown in Figure 1, Remillard and Heck (2014) outlined a conceptual model that situates the important role of instructional materials for mathematics classrooms within a broader curriculum system connecting policy, design, and enactment in educational research. The model recognizes the various ways in which curricula are used across different educational contexts and defines the mathematics curriculum as the “plan for the experiences that learners will encounter, as well as the actual experiences they do encounter, that are designed to help them reach specified mathematics objectives” (p. 707). In this framework, instructional materials are understood as “resources designed to support or supplement instruction, including textbooks, curriculum guides, descriptions of mathematical tasks, and instructional software” (p. 707). These materials are crucial in shaping how the curriculum is enacted in the classroom and, by extension, influencing both teaching practices and student learning outcomes.

In our work, we position our research as focusing on the interaction between instructional materials and the operational curriculum (see red rectangular box in Figure 1). According to Remillard and Heck (2014), the operational curriculum refers to the “actual enacted curriculum in the classroom,” which includes how teachers implement the curriculum, interpret materials, and adapt them based on their unique teaching contexts and the needs of their students. While we acknowledge the insights of Remillard and Heck (2014), we argue in this study that the relationship between instructional materials and the operational curriculum is a dynamic, reciprocal relationship—especially during the processes of designing, field testing, evaluating, and revising curriculum materials. This iterative and continuous feedback loop between the instructional materials and the operational curriculum allows for ongoing adaptation, ensuring that the curriculum remains responsive to both instructional goals and evolving student learning outcomes.

1.2. Theoretical Perspective

To investigate the dynamic interplay between instructional materials and the operational curriculum, we draw on a theoretical perspective grounded in research and practice. Building on the theoretical and empirical underpinnings outlined by Edson et al. (2019) that examine the complex interactions between curriculum design, teacher enactment, and the development of problem-based curriculum materials, our framework highlights how curriculum materials and teaching practices inform and shape one another and the ways in which teachers engage with and adapt these materials over time in mathematics classrooms. As Edson et al. (2019) emphasize, the design of problem-based curricula requires careful attention to identifying important mathematical ideas and embedding them within contextual problems that promote reasoning, problem-solving, and conceptual understanding (Lappan & Phillips, 2009).

To bridge the theoretical and practical dimensions, Figure 2 visualizes the key curriculum design and enactment tensions that arise when developing and implementing a problem-based curriculum. These tensions illustrate the reciprocal relationship between theory and practice in mathematics classrooms. In Figure 2, the curriculum design tensions focus on decisions related to the selection and organization of mathematical content and tasks. These include balancing open and closed tasks, ensuring coherence in the curriculum, and determining the appropriate timing for closure on mathematical concepts. Meanwhile, the teacher enactment tensions center on the challenges teachers face as they bring the curriculum into real-time classroom settings. Many teachers, especially those with limited experience in problem-based environments, often adhere to a mastery-oriented view of mathematics, where they are shown how to solve a problem and then practice the procedure in isolated lessons (Edson et al., 2019). When teachers lack experience with problem-based learning, they may struggle to envision how to create a learning experience that encourages deeper engagement with mathematics. This adds an additional layer of complexity to their efforts to implement the curriculum effectively. The center column of the theoretical framework highlights the features of curriculum materials and strategies that curriculum developers can incorporate to address these interrelated tensions. The goal is to foster effective curriculum enactment that supports meaningful student learning. This framework offers a comprehensive lens through which to examine the evolving relationship between curriculum development and classroom practice, illustrating how curriculum materials evolve in response to teacher feedback and classroom dynamics (Edson et al., 2019).

The theoretical framework presented by Edson et al. (2019) has evolved since its original version, reflecting several key revisions that align with ongoing improvements to the curriculum and an increased emphasis on teacher feedback. As the authors continue to refine their problem-based curriculum, they underscore the importance of balancing skill development with conceptual understanding and addressing the needs of diverse learners. These changes are especially evident in the curriculum design tensions, where more attention is now given to structuring tasks that not only promote procedural knowledge but also foster a deeper understanding of underlying mathematical concepts. Moreover, the teacher enactment tensions have expanded to include a stronger focus on recognizing the embedded mathematical understandings within contextual tasks and supporting teachers in leveraging their mathematical knowledge to guide students through the problem-solving process (Choppin, 2011). One notable addition to the framework is the emphasis on teachers’ ability to recognize and respond to students’ mathematical strategies and reasoning, a key component for fostering an inquiry-driven learning environment. In response to research indicating that teachers often struggle to visualize and implement problem-based learning, Edson et al. (2019) now place greater emphasis on providing teachers with ongoing support in recognizing the embedded mathematics within tasks and designing inquiry-driven lessons. These revisions reflect a more integrated approach to supporting teachers in the effective enactment of problem-based curriculum materials, ensuring that the curriculum continues to evolve to meet the needs of both teachers and students.

1.3. Research Question

While there is substantial research on the teacher–curriculum relationship (Ball & Cohen, 1996), the specific role of teacher feedback in shaping problem-based curricula has not been thoroughly explored. Given that problem-based curricula are designed to foster deeper conceptual understanding and student engagement, understanding how teachers interact with and modify these materials is essential for improving their effectiveness. The objective of this study is to examine the teacher–curriculum relationship in mathematics classrooms by focusing on how teacher feedback from their classroom experiences influences the development of problem-based curriculum materials, particularly in middle grades mathematics. Drawing on the conceptual framework that emphasizes the interaction between curriculum materials and teacher practices, as well as the theoretical framework that highlights the challenges inherent in curriculum design and enactment as described by Edson et al. (2019), another objective of this study is to uncover how teachers perceive the effectiveness and challenges of implementing these materials in real classroom settings. Specifically, the research is guided by the following question:

How do field test teachers perceive the effectiveness of implementing and enacting a contextualized, problem-based middle grades mathematics curriculum and its design features?

Through teacher perceptions, this research aims to provide insights into the relationship between curriculum design, teacher practices, and student outcomes, with the goal of contributing to the ongoing refinement of curriculum materials in response to teacher feedback and classroom dynamics.

2. Materials and Methods

2.1. Methodological Approach

The overarching approach for this development of the curriculum materials follows an iterative, research-informed process, drawing on principles from design-oriented methodologies such as design studies (Edelson, 2002), design experiments (The Design-Based Research Collective, 2003), and developmental research (Richey et al., 2004). These approaches share a focus on refining educational interventions through cycles of design, implementation, analysis, and revision in classroom contexts (The Design-Based Research Collective, 2003; Edelson, 2002; Richey et al., 2004). These approaches aim to produce new theories, artifacts, and practices that impact teaching and learning in real-world settings (Barab & Squire, 2004). The research reported in this study was conducted within the larger design research project, focusing on field test teachers’ perspectives on the effectiveness of enacting a contextualized, problem-based middle grades mathematics curriculum and its design features.

Connected Mathematics^®4 (CMP4; Phillips et al., 2025a, 2025b, 2025c) builds on the foundation set by the Middle Grades Mathematics Project (MGMP). As described in Edson et al. (2019), MGMP (Lappan et al., 1985) helped teachers move from traditional instruction to problem-based learning, with a focus on key mathematical ideas and sequences of problems designed to build understanding. The Launch–Explore–Summarize model developed by MGMP supported this shift and addressed curriculum design tensions, such as identifying core mathematical concepts and sequencing tasks to support deep understanding. It also helped address teacher enactment tensions, such as recognizing varying levels of teacher experience and ensuring effective use of the instructional model.

MGMP teachers reported struggling to apply what they learned from the units across their full curriculum. In response, three of the MGMP authors developed CMP1 (Lappan et al., 1998), which introduced new features to help teachers implement problem-based instruction in a complete mathematics curriculum for grades 6, 7, and 8. Each grade consisted of eight units, each with 2–6 investigations. Each investigation consisted of 1–6 problems. As described in Edson et al. (2019), the addition of Mathematical Reflections at the end of each investigation allowed both students and teachers to pause and assess understanding, addressing curriculum design tensions related to knowing when to close a lesson. CMP1, using the Launch–Explore–Summarize model, also provided extensive teacher support, helping teachers facilitate rich discourse and better navigate the complexities of problem-based teaching, responding to enactment tensions around developing strong pedagogical practices.

CMP2 (Lappan et al., 2006) was developed based on research and classroom experience with CMP1. This version refined problems and teacher support materials to help students develop a deeper understanding. As described in Edson et al. (2019), features like Looking Back, Looking Ahead addressed curriculum design tensions around organizing a coherent sequence of lessons, while the At a Glance feature streamlined lesson planning for teachers, addressing enactment tensions related to managing increasing complexity in materials.

In CMP3 (Lappan et al., 2014), student problems and teacher support materials were enriched with examples of student thinking, helping teachers anticipate how students might approach problems. As described in Edson et al. (2019), this addressed enactment tensions around recognizing and responding to diverse student reasoning. CMP3 also introduced Focus Questions to help teachers maintain focus on key mathematical ideas and guide lesson planning, addressing curriculum design tensions around choosing the right questions to guide student understanding. A one-page resource provided a clearer view of the mathematical progression across units, supporting teachers in managing the flow of concepts and reinforcing the curriculum design tension of developing a connected curriculum.

2.2. The Iterative Development and Field Testing of CMP4

The development and testing of CMP4 field test materials followed a thorough, iterative process involving over 500 teachers over 25 U.S. states and six additional countries (see

Table 1. Overview of the field test teachers for the field test version of CMP4.

Year	Total Teachers	Approximate Number of Unique Schools	States Represented (United States)	Countries Represented
2019–2020	11	10	AZ, IL, ME, MI, NY, OH, TX	United States
2020–2021	13	6	MI, NY, OH	United States
2021–2022	343	155	CA, DE, IL, IN, KS, MA, ME, MI, MN, MO, NC, NJ, NM, NY, OH, PA, TX, VA, VT, WI	Colombia, England, and the United States
2022–2023	515	409	AZ, CA, IL, IN, KS, MA, ME, MI, MN, MO, NC, NJ, NM, NY, OH, PA, TX, VA, VT, WI	Brazil, Colombia, England, the Netherlands, the United States, and Vietnam
2023–2024	319	138	AL, AZ, CA, IL, KY, MD, ME, MI, NC, NJ, NY, OH, PA, TN, UT, VA, VT, WI	Brazil, England, South Korea, the Netherlands, the United States, and Vietnam

). Throughout this process, field test teachers were primarily recruited from those already using the CMP3 materials, with ongoing professional learning and feedback integrated at each stage. The development process began with an initial phase that involved both the CMP team and the publisher. In this initial phase, the CMP development team began conversations to discuss initial changes to the structure and scope of the curriculum. These discussions focused on key topics such as the table of contents, scope and sequence, and unit organization. A major area of focus was the integration of the CMP STEM Problem format (described later in Section 2.3), which was being explored as part of a digital collaborative platform with the Connected Mathematics^®4 seventh-grade curriculum. The early work aimed to align the vision for CMP4 with necessary educational goals, ensuring the curriculum would be both innovative and feasible for classroom implementation. These foundational conversations helped to address some of the curriculum design tensions identified in earlier phases of CMP development.

In Year 1 (2018–2019), formal field testing began, focusing on a select group of sixth-grade units. Early field testing helped to evaluate the new features, including the CMP STEM Problem format (described later in Section 2.3) and the instructional support materials. Feedback from this first round of testing was used to identify areas for improvement and revise the curriculum accordingly. During this year, the CMP team worked closely with a few teachers. A project-developed digital platform funded by the National Science Foundation was also used in parallel with seventh-grade teachers, providing a space for teachers to test the curriculum in a collaborative, digital format. This allowed for real-time adjustments and feedback as teachers engaged with the project-developed digital platform and worked on the same units digitally. The project-developed platform differs from the platform provided by the publisher.

By Year 2 (2019–2020), the field testing expanded significantly, including units from grades 6, 7, and 8. The group of field test teachers included 11 teachers from 10 schools across 7 states. The teachers continued to provide valuable feedback on new features, such as the inclusion of more student reasoning examples and the Focus Questions, which helped guide lesson planning and enactment. Feedback revealed areas for improvement in supporting diverse learners and streamlining the teacher support materials to make lesson planning more manageable. These insights led to revisions and updates, with ongoing collaboration to ensure the materials met the needs of both teachers and students.

In Year 3 (2020–2021), all units for grades 6, 7, and 8 were included in the field testing. This year saw a broadening of feedback, as more teachers participated in testing and provided in-depth insights on how well the curriculum supported problem-based learning and engaged students in rich mathematical problem-solving experiences. The CMP team also continued to make refinements based on feedback related to the teacher’s experience, particularly around managing the increased amount of material and supporting teachers in effective lesson planning and enactment. The project-developed digital platform continued to play a key role in allowing teachers to collaborate and implement the curriculum in a flexible, digital format. The field test in 2020–2021 included 13 teachers from 6 schools across 3 states.

Year 4 (2021–2022) saw the field test units from all grades continuing to evolve. The field test in 2021–2022 included 343 teachers from 155 schools across 18 states, as well as international participants from Colombia and England. Feedback from these participants led to refinements in the curriculum, emphasizing a more cohesive structure, smoother transitions between units, and clearer guidance on orchestrating the problem-solving process. Teachers noted that having a clearer vision of the progression from one unit to the next helped improve both teaching and student learning. The continued involvement of teachers in the field test ensured that the materials remained grounded in classroom realities and continued to evolve in ways that best supported both students and teachers. The project-developed digital platform continued to provide real-time feedback and offered insights into how the curriculum was being implemented across different classrooms.

By Year 5 (2022–2023), the CMP4 units for grades 6–8 were fully field-tested, and significant revisions had been made to the materials. The curriculum was near final draft status, with ongoing minor adjustments. The field test in 2022–2023 included 515 teachers from 409 schools across 22 states, as well as international teachers from Brazil, Colombia, the Netherlands, England, and Vietnam. Surveys and in-depth feedback (through written unit reports and virtual monthly meetings) confirmed that new features—such as the Focus Questions and Mathematical Reflections—were positively impacting both teaching practices and student learning outcomes. The CMP team continued working closely to finalize the materials for wider dissemination, ensuring they met the needs of teachers and aligned with curriculum standards.

In the 2023–2024 academic year, the CMP4 units for all grades were revised and improved based on the feedback received in the previous year. The feedback from the final phase of field testing helped refine the curriculum materials, with a strong emphasis on ensuring that students could build on prior knowledge and deepen their understanding across the full set of units. The units were now ready for broader implementation, having undergone years of feedback, testing, and refinement to become a cohesive, problem-based mathematics curriculum. The field test in 2023–2024 included 318 teachers from 137 schools across 15 U.S. states, as well as international educators from Brazil, England, the Netherlands, and Vietnam. Extensive feedback was provided by teachers in their unit reports and in monthly virtual meetings.

Professional learning for CMP4 field test teachers over the past four years began with a face-to-face meeting that included a small number of CMP3 teachers, teacher leaders, and field test teachers using the project-developed digital platform. From there, professional learning experiences were provided through a combination of webinars, monthly virtual meetings, and informal virtual conversations. These sessions started with introductory meetings and unit overviews, and over time, they progressively focused on specific units and teaching strategies. The professional learning over the years centered on several key aspects, such as an overview of CMP4, which included its philosophy, new student features, and teacher support, along with grade-level overviews that highlighted the development of key mathematical concepts. Teachers were also guided through the instructional model (Launch–Explore–Summarize) and given detailed information on available teacher resources. Unit overviews were provided both synchronously and asynchronously to accommodate varying schedules. Monthly virtual meetings allowed teachers to ask questions, provide feedback, and receive ongoing support. Additionally, extensive written teacher support was made available, offering more in-depth guidance on each instructional phase, including planning, teaching (Launch, Explore, and Summarize), and reflection, with a particular focus on helping teachers deepen their understanding of embedded mathematical concepts. All virtual sessions and webinars were recorded, providing teachers with the flexibility to revisit the material at their own pace. As the years progressed, the professional learning offerings expanded to meet the growing needs of teachers as they implemented CMP4, ensuring they received the necessary support for the successful enactment of the curriculum.

At the end of each field test year, feedback from participating teachers played a critical role in refining the CMP4 materials. Initially, in Year 1, feedback was collected from a small group of teachers who tested the CMP STEM Problem format on the project-developed digital platform. This feedback focused on individual problems and how they were implemented in the digital context. Over the course of the subsequent years, the feedback process evolved to include more extensive forms, which accompanied each unit being tested. The feedback was organized into several key categories, including “big picture” unit feedback, which allowed teachers to reflect on the overall design and flow of the units, as well as problem-by-problem feedback, which delved into specific challenges or successes teachers encountered with tasks. Other categories included feedback on the context of the problems, their applications, connections, and extensions, as well as assessments and teacher support materials. Year-end grade-level feedback helped to gauge the progression and coherence across units for each grade, and a final “big question” invited teachers to reflect on the overarching impact of the materials on student learning. Additionally, the feedback included insights into the effectiveness of the Mathematical Reflections feature, which teachers used to support student understanding throughout the units. This comprehensive feedback loop, collected and analyzed across multiple years, ensured that the materials continuously improved to better support teachers and engage students in rich mathematical problem-solving experiences.

2.3. CMP4 and Its Design Features

The Connected Mathematics Project (CMP) materials are created to support teachers and students in developing deeper mathematical understanding and reasoning. Connected Mathematics^®4 (Phillips et al., 2025a, 2025b, 2025c) extends the successes of its predecessors, CMP1 (Lappan et al., 1998), CMP2 (Lappan et al., 2006), and CMP3 (Lappan et al., 2014). Each revision of CMP was extensively field-tested in its development phases. After the release of each edition, the CMP development team continues to interact with schools. The development team seeks iterative and in-depth input and reviews from teachers, families, administrators, mathematics educators, mathematicians, educational researchers, and experts in reading, special education, equity, and multilingual learners. Most importantly, the enthusiasm of the teachers and the creative, productive mathematical thinking of their students provide the fuel for the authors to think even more deeply about “Can we do more?” The result is “yes!” This continuous interaction with the field and design research is a critical process in the development of CMP4 and is the foundation of the success of CMP, which has withstood the pressures of various political changes since CMP1 was released in 1996.

Connected Mathematics^®4 provides seven student units for sixth grade and eight student units each in seventh and eighth grades. The eighth-grade units offer the possibility of teaching an eighth-grade course or a first-year high school course focused on algebra. Each unit is organized around a big mathematical idea or cluster of related ideas, such as variables and patterns, area and perimeter, ratio and proportion, linear relationships, or nonlinear relationships. The format of the student material promotes student engagement with an exploration of important mathematical concepts and related skills and procedures. Students develop strategies and conceptual understanding by solving problems and discussing their solutions in class.

The CMP4 student material consists of the following components:

Mathematical Goals and Looking Ahead. The mathematical goals guide the development of the big ideas of mathematics for the unit. Each unit opens with three interesting problem situations to draw students into the unit, pique their curiosity and joy in mathematics, and point to the kinds of ideas they will investigate. This is followed by a set of focusing questions that reflect the mathematical goals of the unit. Students can use these questions to help track their progress through the mathematical goals. Students can revisit these questions as part of their reflections on their learning.

Investigations. Mathematics learning is focused on one or two big ideas of mathematics developed through carefully sequenced investigations. Each unit builds toward the mathematical goal of the unit and is comprised of two to four investigations. Each investigation includes the following key elements:

o

2–4 CMP STEM Problems.

o

Did You Know? This component connects the context and/or mathematics to real-life anecdotes.

o

Mathematical Reflections. These contain one overarching question that guides the development of students’ understanding of the big mathematical idea of the unit.

o

Applications–Connections–Extensions (ACEs). This component allows students to reinforce, connect, or extend their understandings.

Student Notebooks. This notebook provides space for students to record their strategies and understandings as they work through a unit.

In this section, we address some of the ways CMP4 has attended to the curriculum design issues (see Figure 3). The design features that address some of the curriculum and enactment tensions are indicated in the middle column labeled CMP4. The numbers next to each design feature refer to a “Curriculum Design Tension” and the letter refers to a “Teacher Enactment Tension”. The bulk of the tensions were addressed by the redesign of the problem format (Figure 4). It includes a more open challenge, which provides multiple ways of accessing it and provides insights into the embedded mathematical understandings.

CMP4’s new CMP STEM Problem format (see Figure 4) promotes learning and problem-solving that resembles the work of STEM professionals. It attends to some of the curriculum design tensions as the context of the problem in the Initial Challenge is more engaging and open, and thus allows for more students to access the challenge. The What If…? feature provides a balance between open and more closed questions in the Initial Challenge, thus guiding the students’ understanding of the embedded mathematical idea in the Initial Challenge feature. The Now What Do You Know? feature of the problem provides an opportunity for students to know what they know. Collectively, the format promotes students’ problem-solving strategies and hence their ability as doers, creators, and communicators of mathematics. In addition, the CMP STEM Problem format provides teachers with flexibility to carry out equitable practices that help address the individual needs of all students. CMP4, using the CMP STEM Problem format and other features, has streamlined the mathematical focus of each unit, resulting in a 17–20% reduction in the number of problems across the grades.

At the end of each investigation, there is now just one overarching Mathematical Reflection question that guides the students’ mathematical understanding of the big idea in the unit. Figure 5 illustrates the Mathematical Reflection for the sixth-grade Variables and Patterns unit. The Now What Do You Know? feature notes can be used to record students’ emerging understanding of the big mathematical idea of the unit that is embedded in the unit’s Mathematical Reflection question.

CMP4 has more examples of student thinking as context for promoting student learning. The student work in Problem 2.1 Situation A (see Figure 6) provides student work that helps students see there that is sometimes more than one way to solve a problem (Zane, Bruce, and Gwen’s Strategies), and there is not always a direct path to the answer (Yvonne’s Strategy). Situation B enhances students’ understanding of proportional reasoning by altering the ratio of cupcakes in each box and by changing the size of the box (or number of total cupcakes). It also provides a transition among representations and generalizations among pictures, words, and tables. The Now What Do You Know? question helps students reflect on their understanding of ratios as a tool for solving problems. CMP4 strengthens the use of visual representations to develop and recall understanding of important mathematical ideas.

Figure 7 illustrates the Mathematical Reflection for the sixth-grade Comparing Quantities unit. The Now What Do You Know? feature provides student notes for recording their emerging understanding of the big mathematical idea of the unit, which are then consolidated into the Mathematical Reflection question. For example, the Now What Do You Know? feature in Problem 2.1 in Figure 5 can provide students with evidence of students’ understanding of ratios at this stage of development in the unit.

There are more problems with embedded card sorts, models, matching, games, and experiments. These formats promote active engagement by requiring students to manipulate, categorize, visualize, and reason about mathematical concepts, rather than passively absorb information. For example, card sorts and matching tasks prompt learners to identify relationships among representations, quantities, or strategies, encouraging them to justify their thinking and articulate reasoning. The use of visual or physical models facilitates students’ ability to represent and make sense of abstract mathematical ideas, supporting the development of conceptual understanding. Games and experiments introduce playful yet structured contexts in which students can explore mathematical ideas, offering multiple entry points and promoting inclusive participation. These interactive formats often foster collaboration and discourse, providing opportunities for students to engage in mathematical argumentation and refine their ideas through peer interaction. Additionally, such activities serve as rich sources of formative assessment, allowing teachers to observe students’ thinking in action and respond to their needs in real time. For example, in Figure 8, a game is used to strengthen students’ understanding of integers. In Figure 9, a card sort (matching) of graphs, equations, and contexts is used to pull together the key understanding of linear functions.

The following activity (see Figure 10) is an experiment that investigates some of the variables that affect the strength of a bridge. In this experiment, the two variables are the thickness of the bridge and weight. The relationship is linear. In Problem 1.2, they repeat the experiment, looking at the length of the bridge and the weight. This relationship is not linear. It is an inverse relationship.

The prior figures in this section illustrate problems from various units. Figure 11 provides an overview of the units for grades six, seven, and eight. In CMP4, there are stronger connections both within and across units and grades. CMP4 strengthens its unique development of algebra and functions, which continues to develop exceptionally strong student algebraic understandings. Starting with Variables and Patterns as the first unit in grade 6 allows the use of patterns of change and equivalence, representations, and generalization to naturally arise in all the remaining 22 CMP4 units, ending with the Function Junction unit in eighth grade. The unit titles highlight the main contextual thread and the mathematical focus. The mathematical focus for each grade is highlighted in the first row of Figure 11. The focus of the 8th grade on algebra and functions serves the needs of both grade 8 and High School Course 1.

CMP4 has a stronger, more robust development of proportional reasoning starting with a new grade 6 unit, Comparing Quantities, and continuing with several units in grades 7 and 8. CMP4 incorporates aspects of the statistical problem-solving process throughout all units. The first problem in the first unit of each grade starts with an experiment.

To address some of the teacher enactment tensions, CMP4 (Phillips et al., 2025a, 2025b, 2025c) provides more support for teachers in its CMP Arc of Learning™ Framework (Edson et al., 2019) for each unit, CMP Formative Assessment Framework, CMP Attending to Individual Needs Framework, embedded General Pedagogical Strategies, and its new At a Glance teacher support for each problem. These were not robust enough to be fully implemented during field testing. However, the teacher’s comments on the student materials provided insights into the teacher support documents.

The Arc of Learning™ Framework provides guidance on how the understanding of the big mathematical idea for the unit evolves. In Figure 12, the Arc of Learning™ Framework is shown for the first unit on proportional reasoning in sixth grade and a third unit of proportional reasoning in seventh grade. The development of proportional reasoning is growing toward abstracting. There are three more seventh-grade units that continue to look at proportional reasoning in the context of linear relationships, probability, and statistics.

The Attending to Individual Learning Needs (AILNs) framework (see Figure 13) communicates to teachers the information learned from research and practice over 40 years of field testing in CMP classrooms. It is consistent with the teaching practices set forth by other organizations. The appropriate component of the AILNs framework is indicated in the Launch, Explore, or Summarize phase of instruction in the At a Glance guide for the teacher.

At a Glance is a two-page format that provides the important information needed to implement a CMP4 problem. More details for the Launch–Explore–Summarize instructional phases of a lesson are provided in an extended Launch–Explore–Summarize section. Figure 14 is an example of an At a Glance for Problem 2.1 in the 6th grade Comparing Quantities unit. In addition to supplies, pacing, and grouping information, it also provides a sample of questions that can be used during each phase of the lesson. The appropriate Attending to Individual Learning Needs framework is indicated, as well as a suggested pedagogical strategy. Corresponding applications, connections, and extension task suggestions are also included.

2.4. Data Collection

At the close of the 2022–2023 school year, a total of 233 teachers, coaches, and administrators who field tested CMP4 completed a survey about their experience with the curriculum. This was the final year of field testing that provided substantial feedback to inform the published version of CMP4. Recruitment of field test teachers throughout the development process primarily focused on CMP3 teachers, coaches, and administrators, reflecting an intentional effort to gather feedback from educators familiar with prior editions of the curriculum. This provided feedback that was crucial for evaluating how the fourth edition field test materials built upon, refined, or changed previous versions. However, the inclusion of newcomers—such as teachers newly hired into CMP districts and a small number of non-CMP3 schools—was also essential for capturing a broader range of perspectives. Some non-CMP schools participated in field testing, primarily because they requested involvement due to professional learning efforts that made use of the materials with neighboring districts. These educators brought fresh views on the curriculum’s usability and effectiveness for schools that had not previously implemented CMP, offering a unique opportunity to assess how CMP4 field test materials performed in diverse instructional settings.

The survey was conducted electronically at the end of the school year, with responses from stakeholders (teachers, coaches, and administrators) representing approximately 70 cities spanning 20 states in the United States, as well as three additional countries. The participating schools represent a wide range of diversity in terms of gender, race, ethnicity, economic status, and/or disability. The socio-cultural diversity of the countries represented brings a variety of perspectives, each shaped by distinct educational contexts, which may influence how teachers and students engage with the field test materials. This diversity adds complexity to the interpretation of the results, as socio-cultural factors likely affect the implementation and effectiveness of the curriculum in different ways. Given the diversity in the socio-cultural and educational contexts, the design of the survey was intentionally developed to capture a broad range of feedback on the curriculum’s features, effectiveness, and student engagement across varied instructional settings. The survey was built on prior CMP curriculum development and research efforts in middle school mathematics classrooms, and included items specifically focused on the design features of the fourth edition of the materials. The survey included approximately 10–15 quantitative items (e.g., multiple choice, Likert scale, and frequency questions) addressing the courses taught, frequency of collaboration with teachers and/or coaches, students’ levels of math engagement and learning, and the effectiveness of the curriculum and its features. Participants were also asked two open-ended questions: one inviting them to share encouraging stories from teachers, and another asking how they would describe CMP4 to someone unfamiliar with the curriculum. Survey items were developed based on prior CMP research addressing curriculum effectiveness, student engagement, and implementation experiences and reviewed for clarity and alignment with study goals. The results were analyzed using descriptive statistics and inductive coding to identify patterns across diverse instructional settings.

2.5. Data Analysis

The survey was analyzed based on data from both the quantitative and qualitative items answered in the survey. To begin the survey analysis, identifying information was removed from the individual responses, such as first name, last name, and email address. Each quantitative question was then examined for the number of responses and the percentages of each answer. The quantitative questions most closely explored the effectiveness of the curriculum and its embedded features, with a focus on those that promoted mathematics engagement and learning. Effectiveness was measured using a Likert scale in two ways: one scale ranged from 1 (“less effective than last year”) to 3 (“about the same as last year”) to 5 (“more effective than last year”), while another scale ranged from 1 (“not effective”) to 3 (“somewhat effective”) to 5 (“very effective”). Simple summary statistics were used to analyze the data, including frequencies and percentages, to examine trends in responses. This analysis allowed the CMP4 team, including curriculum developers, to identify which features were found to be the least and most effective, as well as those that were less well known. The analysis of the qualitative responses focused on identifying patterns or themes across the responses, with an emphasis on features and stories that supported mathematics engagement, learning, problem-solving, sharing multiple solutions, and working through real-life contexts. Most participants were CMP3 users and therefore had prior familiarity with the CMP materials. While the Likert scales were not formally validated, they were designed to capture key aspects of curriculum effectiveness and engagement based on prior research and expert input. These findings, both quantitative and qualitative, will inform future curriculum revisions and professional learning for teachers.

3. Results

3.1. Result 1: CMP4 Problems Promote Student Engagement and Learning in Mathematics

Our survey analysis showed that over 95% of teachers felt that their students were the same or more engaged in mathematics and critical thinking when field testing CMP4. The survey data showed that 66.52% of teachers (n = 155) indicated CMP4 was more effective in promoting student engagement and critical thinking when compared to the prior year. The prior year’s curriculum ranged from earlier versions of CMP to teacher-generated materials. Further, our analysis found that approximately 30% of teachers (n = 65) believed that student engagement and critical thinking were around the same level as last year. Only four teachers (<2%) found that engagement and critical thinking in CMP4 classrooms were less than in the prior year.

CMP4 promotes students’ engagement and learning in mathematics by allowing students to be knowers and doers of mathematics. Niss et al. (2016) discuss the intricate relationship between knowing mathematics and being a “doer” of mathematics. According to Anderson (2007), “all students can become mathematics learners, identifying themselves and being recognized by others as capable of doing mathematics” (p. 7). The notion of being a doer of mathematics is furthered by CMP4 Problems, which are “a more hands-on math curriculum that requires more critical thinking and analytical reasoning from students”. The focus on CMP4 Problems allows students to engage in small and whole-group collaboration with their classmates. A teacher stated that CMP4 “encourages collaborative learning and problem-solving strategies that leads to students’ academic success”. Another teacher said CMP4 “is a different approach that leads students to critically think and take ownership of their thinking processes”.

Figure 15 addresses the effectiveness of the highlighted design features as perceived by the field test teachers. Our analysis of the survey found that the CMP STEM Problem format was an important curriculum design feature that teachers used to promote student engagement and learning. Out of 233 total respondents, approximately 90% of teachers (n = 199) rated the CMP STEM Problem format to be somewhat effective, effective, or highly effective in promoting engagement and learning (see Figure 16). While many teachers found the CMP STEM Problem format effective, approximately 7% of the teachers did not know this format existed. Teachers found that the CMP STEM Problem format allowed students to extend their thinking and problem-solving skills. These skills are further discussed by a teacher stating, “CMP4 is a math curriculum that engages students in critical thinking, problem solving, and mathematical discourse”.

Our survey analysis found that teachers valued collaboration as a key component to student engagement and learning in math. Teachers appreciated that small-group and whole-group collaboration support was built into the curriculum program. Additionally, teachers appreciated the ability to use a problem-based curriculum that encourages collaboration. This is shown by a teacher saying, “There is nothing better for learning mathematics than a problem-based program that encourages students to collaborate and build understanding”. Specifically, teachers found that the curriculum design features and the various supports for students to demonstrate engagement and learning, such as matching, card sorts, games, and experiments, were beneficial. The survey results indicated the benefits of “problems with embedded card sorts, models, matching, games, and experiments” to be approximately 18% somewhat effective and approximately 65% effective and very effective. The problems that are in CMP4 allow students to engage with mathematics through a collaborative environment where students can see themselves reflected in the mathematics they are learning.

The survey analysis also indicated that CMP4 promotes student engagement in mathematics. A teacher stated, “students become better problem solvers and are truly engaged when they can collaborate and ’talk’ math in real world scenarios”. The survey results indicated that 40% of teachers (n = 92) found student engagement to be the same as last year using CMP4, while 55% of teachers (n = 129) found student engagement to be better than the previous year. It was noteworthy in our analysis that teachers’ qualitative responses spoke directly to the distinction between engagement in class and engagement in the embedded mathematics. For example, the CMP4 Problems provide the opportunity to “engage students into math discussions” and “students have also displayed deeper conversations and collaboration through the use of this version”.

While our analysis supported the finding that students’ communication using mathematical language was the same or more effective than last year using CMP4, there were a few CMP4 teacher material features in which over 15% of teachers indicated they were unfamiliar with these features. For example, approximately 22% of teachers responded that they did not know there was a feature in CMP4 that attends “to Individual Learning Needs Framework with embedded supports in Launch—Explore—Summarize for diverse learners and language development” (see Figure 15). This is demonstrated by a teacher in the survey saying “Good curriculum—but I still need to supplement for more skill practice and for lower performing students. I especially had to supplement for our students with IEP math goals”. This shows that this teacher needed additional supports that they had access to but were not aware existed. A teacher stated, “As a multilingual specialist who works in 7th grade as a co teacher, I would like to see more videos, visuals, and support for multilingual learners”. Two additional features that almost 27% of teachers did not know about are “Overview videos discussing the mathematics of the Units” and “Welcome and general video recordings about CMP4”. These features could be beneficial for teachers and/or students to have access to when they need to refer to overviews.

3.2. Result 2: CMP4 Problems Support Students in Solving Problems, Making Mathematical Connections to Real-Life Applications of Mathematics, and Sharing Multiple Solution Strategies

CMP4 Problems consist of contextualized problem situations that embed mathematics. This provides a storytelling aspect within the mathematics problems that provides an opportunity where students are “actively engaged in their learning and can talk about math”. “Students participating in discourse” was rated to have approximately 40% effectiveness, which was the same as last year using CMP4, and approximately 54% effective or more effective than the previous year. When teachers were asked about what they would tell someone that was not familiar with CMP4, one teacher stated that “CMP4 is a highly rigorous curricular resource that promotes student engagement and discourse through story-based contexts and problems”. This was furthered by another teacher who stated that CMP4 “leads to a mathematical discussion of deep value on a daily basis”. A key aspect of CMP4 that teachers find particularly useful is the ability to promote mathematical discussion through “talking math”. Using a Likert scale for measuring students’ communication with mathematical language, as noticed by the teacher, our analysis showed that teachers indicated that “students communicate using mathematical language”. Nearly 45% of responses (n = 100) indicated teachers thought students’ communication with mathematical language was the same as last year. Further, 51.50% (n = 120) rated it to be more effective than the previous year using CMP4, while a combined percentage of only 5.58% (n = 13) rated it as less effective. One teacher indicated that “CMP4 encourages student discussion and articulation of math ideas”, while another teacher said, “students discuss math and relate ideas to each other”. The survey data demonstrate how the problems in CMP4 promote student discussion and collaboration within the classroom, as reported by the teacher. CMP4 Problems provide students the opportunity to connect to the problems through storytelling while also pushing students to engage in mathematical discourse by communicating in mathematical language.

The survey analysis indicated that an important aspect of CMP4 is supporting students in solving problems and providing the opportunity for mathematical connections to real-life applications. An important part of mathematics learning in CMP classrooms is the ability to see how the mathematics in the classroom relates to everyday life. In the survey, a teacher shared that “CMP4 is an excellent way for students to not just ‘do’ math problems, but to analyze real life situations and apply math concepts in daily situations”. Another teacher stated that CMP4 “allows students to take control of their learning and form a deeper understanding of mathematical content and its connection to the real world”. A benefit of CMP4 that was noted by many teachers throughout the survey is that students were able to see themselves in mathematics, which allowed them to make connections to their daily lives. A teacher of CMP4 stated that the problems that comprise CMP4 “allows for students to see themselves in the mathematics and work on creating a sense of positive mathematics experiences for students to be successful in class”. Therefore, CMP4 provides an opportunity not only for students to make connections with everyday life, but also to see themselves in the mathematics they are learning.

Additionally, while CMP4 allows students to make connections to math and their daily lives, it also allows them to see the connections between math concepts from multiple units. This connection is demonstrated by a teacher stating, “CMP4 has helped my students make authentic mathematical connections using real world applications”. A different teacher said that their students “are able to collaborate with one another and see each other as contributors and doers of math. Students’ ability to share their thinking, model, and discuss with each other has improved”. CMP4 Problems connect school math and real-life math by allowing students to see themselves and their everyday lives in the mathematics that they are learning in school.

A characteristic of CMP4 Problems that resonate with teachers is the ability to make connections to prior concepts while continuing to build toward future concepts. CMP4’s use of context problems creates a space where students are “challenged to think and discuss math in a way that has them remembering the context of unit problems all year long”. This alignment is emphasized by a teacher stating that “CMP4 use of real-world problems through the initial challenge, exploration and summary is wonderful in connecting students with all levels of abilities to math concepts”. The curriculum allows students to “access prior knowledge” while “building connections across content and units”. Additionally, CMP4 Problems are “cyclical and continue to reinforce essential concepts throughout several of the units”. It was stated that “CMP4 encourages students to think critically and approach math in multiple ways….CMP4 promotes multiple strategies and connections between concepts rather than a one-and-done way to solve a problem”. CMP4 Problems allow students to engage in mathematical discourse while making connections from past units and looking forward to future concepts.

4. Discussion

In this paper, we reported on the bi-directional relationship between instructional materials and the operational curriculum. We provide evidence for offering an alternative to the one-directional model proposed by Remillard and Heck (2014), which traditionally emphasizes the influence of materials on classroom practice without fully accounting for the reciprocal impact of classroom enactment on materials. As research has shown, teachers play a central role as mediators between curriculum materials and student learning (Ball & Cohen, 1996; Ben-Peretz, 1990; Pepin, 2019). Our study highlighted how feedback from field test teachers provides empirical evidence of a dynamic, reciprocal interaction between curriculum design and classroom enactment. While Remillard and Heck (2014) emphasize the influence of instructional materials on classroom practices, our study shows that teachers’ adaptations and classroom practices also shape the curriculum materials. This aligns with findings from Stein and Kim (2009), who emphasized that teacher engagement with curriculum materials directly shapes how these materials are enacted in the classroom. What distinguishes this study from prior work is the use of design research methods to systematically collect and integrate teacher feedback throughout an extended development cycle. This represents a new contribution by demonstrating how iterative developer–teacher collaboration, embedded in a field test structure, informs curriculum refinement. Thus, our study reports evidence of a cyclical, iterative process, consistent with design research approaches (The Design-Based Research Collective, 2003; Edelson, 2002; Richey et al., 2004), where teacher feedback informs ongoing revisions to the curriculum before it is published. Teachers noted how certain problems and concepts were revisited across several units, reinforcing the evolving nature of the development of mathematical understanding embedded in the curriculum. This was particularly evident in the feedback about the CMP STEM Problem format, which teachers reported helped support student understanding across contexts. These findings highlight the importance of viewing the relationship between instructional materials and the operational curriculum as bi-directional, contributing to the improvement of both teaching practices and student learning outcomes.

Like Spagnolo et al. (2021), this paper reported on the design, field testing, and evaluation of the field test version of the fourth edition of a contextual problem-based curriculum, CMP4, which engaged over 500 teachers from the U.S. and internationally. While Spagnolo et al. (2021) used large-scale assessment as a framework and teacher beliefs to design a distance professional learning experience over one year culminating in a survey, the research reported in this study made use of a curriculum design and teacher enactment framework that guided the development, field testing, and evaluation of CMP4 over four years. The findings from the 2022–2023 survey highlight the effort to make CMP’s STEM Problems both expansive and focused enough to foster a deep understanding of the mathematical learning goal. Additionally, the tensions in both curriculum design and teacher enactment, as outlined in the theoretical framework, are underscored in this study. Survey quotes suggest that students were able to make connections from mathematics to their daily lives, take more control of their learning, engage more effectively in mathematical discourse, draw connections both across units and within a unit, and see themselves as doers and contributors of mathematics. These responses align with the framework’s emphasis on the importance of designing contextual mathematics problems that not only support procedural knowledge but also encourage deeper conceptual understanding (Edson et al., 2019; Lappan & Phillips, 2009). These data suggest that the CMP STEM Problem format in CMP4 was effective in promoting these outcomes. This study contributes new insights by systematically capturing teacher perceptions of a specific problem structure—CMP STEM Problem format—and its influence on student engagement and learning across a large and diverse sample of classrooms. These findings highlight the critical role of student involvement in the development and enactment process. As teachers continue to adapt the curriculum and its design features to meet the evolving needs of students, it is essential to prioritize problems that balance both conceptual and procedural development while fostering deeper student engagement. This cyclical interaction between curriculum design, teacher enactment, and student outcomes reflects the evolving nature of problem-based learning, where both teachers and students actively contribute to the shaping of the curriculum.

Nonetheless, this study is not without limitations. In addition to the absence of student performance data, there were several other factors that may influence the interpretations of the findings. One key limitation is potential selection bias: many of the field test teachers were already familiar with CMP, particularly CMP3. Their prior experience and alignment with the CMP philosophy may have shaped their perception and feedback, potentially leading to more favorable evaluations of CMP4. While this group provides valuable insights into how CMP4 builds on its predecessors, future studies should intentionally sample teachers with no prior CMP experience.

While the data provided by the survey offer substantial support for the claims about the effectiveness of the CMP STEM Problem format, a key limitation is that it reflects only teachers’ perspectives on classroom implementation of the print-based materials. The survey sought teachers’ insights into the effectiveness of various paper-and-pencil curriculum features, the use of materials, and their perceptions of what they would share about CMP4. The respondents highlighted positive feedback, including praise for how the curriculum materials engage students, strengthen problem-solving and critical thinking skills, and enhance enjoyment of mathematics, with some noting improved student performance data and students seeing themselves as active participants in mathematical thinking. Specifically, the survey indicated that CMP4 Problems promote student engagement and learning in mathematics, as well as support students in solving problems, making mathematical connections to real-life applications, and sharing multiple solution strategies. However, the survey did not include classroom data or performance metrics and thus lacks student voice to further validate or triangulate these claims. Finally, although the findings are grounded in CMP4’s development context, they have implications beyond this specific curriculum. The design research model described here—where teachers are active contributors to iterative design—offers a model that could be adapted by other curriculum development teams. Insights about the use of problem structure to foster mathematical reasoning, real-world connections, and multiple solution strategies may be generalizable to other mathematics curriculum materials aiming to increase student engagement and conceptual understanding. Future research could extend this study by directly examining student learning and engagement, tracking patterns of change over time, and focusing on the classroom enactment of the curriculum using the published version. Future research could provide a deeper understanding of how teacher support materials address enactment challenges, further refining the curriculum and its impact on students’ mathematical development. Further studies could also explore how the principles of the CMP4 design model might inform curriculum development efforts in other subject areas or educational contexts. Future activities could also focus on students’ mathematical understanding and problem-solving strategies—including those of special populations of students—by anticipating possible student responses and using these expectations to inform planning, teaching, assessing, and reflecting on student thinking.

5. Conclusions

Our study highlights the crucial role of teacher feedback in refining instructional materials, supporting the view that ongoing collaboration between educators and curriculum designers is essential for creating adaptable and effective resources (Ball & Cohen, 1996; Ben-Peretz, 1990; Jones & Pepin, 2016; Pepin, 2019; Stein & Kim, 2009). The survey of 233 teachers, coaches, and administrators in 2022–2023 found that CMP4 Problems promote student engagement, enhance problem-solving skills, and help students make real-world mathematical connections. Additionally, we challenged the one-directional model of curriculum development proposed by Remillard and Heck (2014), presenting evidence of a bi-directional, cyclical relationship between instructional materials and classroom enactment. Teachers’ feedback played a pivotal role in shaping the curriculum, demonstrating the iterative process of refinement. A key limitation of this study is the reliance on teachers’ perspectives without direct classroom data or student performance metrics. As a result, while the findings offer strong evidence of perceived effectiveness from the teacher’s perspective, they do not allow for direct measurement of student learning gains. This limitation is important to consider when interpreting claims about the impact of CMP4 on student outcomes, as they are based solely on teacher-reported observations rather than empirical achievement data. Future research, from researchers outside the curriculum project, should investigate student feedback and assess learning outcomes to validate the curriculum’s effectiveness. For curriculum developers, this study illustrates the value of design-based research in iteratively refining materials based on real-world classroom enactment. For teacher educators, CMP4 provides an example of how curriculum materials can also serve as educative tools, supporting teachers’ professional learning through embedded structures and features of the curriculum materials. For policymakers, these findings reinforce the importance of long-term investments in curriculum development efforts that treat materials not just as static products but as evolving supports for both student and teacher learning.

Overall, the CMP4 field test materials offer a model of curriculum development that addresses both instructional design and learning simultaneously. The findings underscore the value of curriculum problems that are designed in collaboration with teachers to promote student engagement, support problem-solving, encourage connections to real-life applications, and foster the sharing of multiple solution strategies. These results affirm the critical role of teacher–curriculum interaction in shaping meaningful mathematical learning experiences across diverse educational settings.