The observed positive effects of size may be due in large part to the fact that large districts often have more Eisenhower money to spend on professional development than do small districts. Although Eisenhower funds available on a per-teacher basis are comparable, a critical mass of funds available in larger districts may allow them to offer a wider range of types of professional development, and to offer activities that span over longer periods of time. Larger districts may also tend to have more resources of other sorts, such as nearby universities, that will allow them to tap into a wider range of professional development types. In addition, large districts also have a more comprehensive, efficient infrastructure for planning and delivering professional development. This may allow them more opportunities and resources to shape and organize their professional development activities to be more sustained and intensive, and to be responsive to the needs of whole schools or groups of teachers from a school, rather than just individual teachers.
Consortia seem to operate primarily like large districts.
They provide significantly more opportunities for active learning and more types of activities than do small districts. In addition, in many cases consortia provide the same higher levels of collective participation and participation in reform approaches to professional development that large districts do. Thus, it appears that consortia, with similar capacity and resource advantages, enjoy the same positive effects of size as do large districts.