The purpose of the CDT is to provide information that will help guide instruction by providing support to students and teachers. The CDT reports are designed to provide a picture or snapshot of how students are performing in relation to the Pennsylvania Assessment Anchors & Eligible Content and Keystone Assessment Anchors & Eligible Content. (Mathematics and English Language Arts are aligned to the Pennsylvania Core Standards. Science is aligned to Pennsylvania Assessment Anchors and Eligible Content.) Because the CDT is diagnostic in nature relative to student acquisition of the standards, the data may be used to dig deeper and form flexible groups based upon changing student needs. Teachers can then conduct ongoing formative and summative assessment to determine with students whether they are making progress or not.