Interestingly primary school colleagues have always recognised that professional development is more effective when the schools approach is not through one off, episodic and fragmented workshop sessions but rather as a sustained, coherent and intense part of a whole school approach linking curriculum, assessment, standards and professional learning around a theme that the school wants to address. Research suggests that collaborative approaches that develop communities of practice to promote whole school development that extends beyond individual classrooms have the greatest impact on standards and outcomes. This approach also provides a framework for reflection and feedback, allowing teachers to raise issues, take risks and address their own practice.
Although time is not the only variable that matters, it is a prerequisite for effective learning. Research has shown that the teachers that who engage in high quality, sustained and intensive professional development go on to produce significant improvements in student achievement. Research I have read, and re-read recently, shows that professional development lasting 14 or fewer hours showed no effect on student learning while programme offering more than 14 hours of sustained teacher learning opportunities showed positive effects. The largest effects were found for programmes offering between 30 and 100 hours spread out over 6-12 months.