This paper reports on a design-based implementation study of the use of a diagnostic classroom assessment tool framed on learning trajectories (LTs) for middle grades mathematics, where teachers and students are provided immediate data on students' progress along LTs. The study answers the question: "How can one characterize the challenges…

"Informed math self-placement," a program implemented at American River College in Sacramento, California, to determine students' readiness for college-level math, has been in place for three years. This case study describes the development and implementation of math self-placement at American River. Math self-placement consists of a…