Supporting the development of teachers – creating the conditions and processes in which they build their skills, knowledge, and practices – is the cornerstone of any effective curricular change initiative. When considering how best to support teachers, Gardner and Shulman remind us that it is not enough to focus on the routine work of teachers. Instead, we need to understand the complex choices and ambiguities teachers face in their professional work as facilitators of learning. We must assist teachers to expand their skills and practices to perform at “the uncertain limits of their previous experience.” Moreover, we must design ways in which teachers can learn from and with one another as well as share their insights with a broader community of educators.
 
At the heart of effective teaching are several perennial questions such as, “What should my students learn and why? Who are my students and how will they learn in a deep and lasting way? How will I and the learners know that they have learned?” Answers to these questions entail making critical choices about educational content, pedagogy, and assessment. Teachers must grapple with and develop answers to these questions. Avoiding such questions, exploration, and choices delegitimatizes their professional practice. Instead, teachers must be supported and entrusted to navigate inherent uncertainties as facilitators of learning in order to make judgments that benefit the learners, communities, and larger society. Although not easy, the effort is particularly vital when the goal of a curriculum is to develop citizen-learners.
 
Building on the initial Citizen-learners white paper (Krechevsky, Wilson, & Gonzalez, 2020), this companion paper describes in greater detail various teaching techniques and tools that support citizenlearners. We propose core principles of, and effective programs for, high-quality teacher professional development of citizen-learning practices. Our proposal is informed by key findings and experiences from over 50 years of Project Zero educational research into teaching practices and development. We also draw on broader trends in education regarding the evolving expansion of teachers’ role from deliverer of knowledge or “sage on the stage,” to include learning coach, facilitator, or “guide on the side.” We include examples from different classrooms and schools using Project Zero ideas to illustrate what these principles, pedagogies, and professional development programs look like.