As the issues and problems that challenge education and the teaching profession become increasingly complex, our collective need for innovative solutions and new knowledge for learning in diverse educational contexts increases. Yet school leaders and classroom teachers often fail to see a connection between educational theory and research conducted in universities and the real-world, complex and contextually rich teaching, learning and leading contexts in schools. Design-based research (DBR) is one response to the gap between theory and practice in education, to the resounding call for change and innovation in education systems, and to the need for teachers to continually develop the principled practical knowledge required to design authentic, challenging and engaging learning experiences for students.
Dr. Carl Bereiter contends that the theory and practice gap in education cannot be filled solely by practice knowledge or by traditional research. Instead, Bereiter argues that principled practical knowledge “goes to a depth that is sufficient for a field of practice to advance”. “Best practice, evidence-based practice, and reflective practice all refer to ways of making optimum use of know-how”; however, while necessary, these are insufficient for creating new insights into practice, or “know-why” directed towards advancing practice. From our research, design-based professional learning appears to develop principled practical knowledge. Having spent the past 15 years immersed in numerous design-based professional learning studies, our findings would confirm Bereiter’s assertions. 
Design-based research focused on teachers’ professional learning employs research processes and methods to create and study innovation in authentic learning contexts. Within design-based research, solutions to complex problems of practice are conceptualized and then implemented and studied iteratively and collaboratively by researchers and teachers in natural settings. We contend that design-based research is necessary to create and identify productive innovations with participant teachers. Design-based professional learning, which builds upon design-based research findings and theories, provides the bridge for teachers to advance practice in a principled, practical way.
Researchers and mentor teachers from the Galileo Educational Network have adopted design-based professional learning as a way of assisting administrators and teachers to build upon the design-based research for improving student outcomes – defined as student achievement, engagement and well-being. Teachers learn to design worthwhile learning tasks and assessments for students based upon the deep understandings this work is intended to sponsor. Teachers learn to bring forward evidence of the students’ learning, to analyze and determine how that student work reflects the deep understandings identified in the design, and to determine next learning steps for students and next teaching steps for themselves. Teachers engage with each other, researchers and mentors through an iterative process of design, enactment, evaluation, and redesign. Teachers learn to:
- identify what deep understandings their students must build to make learning advances;
- collaborate with colleagues, researchers and mentors from the Galileo Educational Network to design worthwhile tasks, activities, and assessments for their students directed towards building these understandings;
- bring forward evidence of student learning to determine the ways in which their students built deep understanding;
- discern which instructional practices led to improved student learning and understanding; and
- assess the impact of these improved or changed teaching practices on student learning.
Through this design-based, iterative learning process, classroom teachers gain principled practical knowledge, “know-how” and “know-why”.
We have found that design-based approaches to professional learning – ones that have an explicit goal of improving student outcomes (achievement, engagement, and well-being) through assisting teachers in developing principled practical knowledge – is rare. Teachers in our design-based studies and design-based professional learning sessions report that episodic events, under the guise of professional development, still dominate. While design-based professional learning is more time consuming, we have found that this approach provides teachers with the necessary knowledge to advance their practice and provides a way for teaching to become a scholarly activity.
 Jacobsen, M. (2014). Design based research: Sponsoring innovation in education. Education Canada, 54(5), 22-24. Retrieved from: http://www.cea-ace.ca/education-canada/article/design-based-research
 Bereiter, C. (2013). Principled practical knowledge: Not a bridge but a ladder. The Journal of the Learning Sciences, 23(1), 4-17. DOI:10.1080/10508406.2013.812533
 Jacobsen, M., Lock, J., & Friesen, S. (2013). Strategies for engagement: Knowledge building and intellectual engagement in participatory environments. Education Canada, 53(1), 14-18. Retrieved from: http://www.cea-ace.ca/education-canada/article/strategies-engagement
 Jacobsen, D. M., and Friesen, S. (2011). Web Exclusive: Hands On vs. Hands Up: Technology-Enabled Knowledge Building in High School. Education Canada, 51(3). Online: http://www.cea-ace.ca/education-canada/article/web-exclusive-hands-vs-hands-technology-enabled-knowledge-building-high-sch
 Friesen, S. (2009). Teaching effectiveness framework: A framework and rubric. Canadian Education Association. Retrieved from: http://www.galileo.org/cea-2009-wdydist-teaching.pdf