School districts and states across the US are engaged in a
process of standards-based reform built around the Common
Core State Standards. They recognize that progress in most
classrooms depends on their assessment program matching the
new and broader curriculum goals, focused on students’
developing the expertise described in the *mathematical
practices.* This means moving to include performance
assessment.

The Mathematics Assessment Resource Service (MARS) works with districts and states on the design and implementation of performance assessment, and on professional development for designers and teachers. The aim is to help the local leadership develop local capacity to meet local needs. There is a widespread demand.

Our major current project is the Mathematics
Assessment Project (MAP), developing formative assessment
lessons and rich summative performance tasks to support the
Common Core State Standards, emphasizing the vital *mathematical
practices* they require. Many other agencies are using
these products at the heart of reform programs with new
approaches to both curriculum and professional development.