Also below are two outstanding references on Formative Assessments.
The first is from the Wisconsin Center for Educational Research a "Focus on Formative Assessment".
The second is from the National Middle School Association on Formative and Summative Assessments in the Classroom, by Catherine Garrison and Michael Ehringhaus.
These articles, readily available on the web, are shared for academic use only. Any use of them should be properly attributed to the original sources.