Reflections on the increasing relevance...

This paper focuses on commonalities and differences
of three approaches to large-scale professional
development (PD) in mathematics education, based on two
studies from Germany and one from the United States of
America. All three initiatives break new ground in improving
PD targeted at educating “multipliers,” and in all
three cases specific design principles for successful PD
are defined, implemented, and discussed. All three teams
systematically investigate the success of their PD activity
and thereby discuss their theoretical assumptions, research
questions, methods, and results. Given the goal of scaling
up, the initiatives are pilot projects due to the relatively
small number of participants. The paper highlights the
diversity of approaches, each including various specific
strengths but also some limitations. This is done by analyzing
the three studies regarding the features “large-scale
PD and scientific knowledge on it”, “goals and design of
PD”, “research design and methods”, and “research results
and implications”. Overall, the studies help to understand
the enormous challenges of the field when aiming at largescale
PD and systematically investigating and reflecting its
impact. One prominent challenge is teacher educators’ double
role of intervening and investigating. All three studies
recommend a continued or even stronger focus on participants’ practice and its challenges. It makes sense to assume that the focus on participants’ practice and strengths is even more important when starting further cascades.