. . "Teachers can review existing student work such as writing samples or test results, conduct conferences with students, or observe them to get a sense of their current skill level. (See The Center???s December 2006 newsletter, Using Classroom Assessment to Improve Teaching, at http://www.centerforcsri.org/files/TheCenter_NL_Dec06.pdf for more information.) Formal or informal, the key to the successf" . .