"Specific Mathematics Assessment that Reveal Thinking" (abbreviated as "smart tests") provide an on-line formative assessment of middle years students. They aim to put information from research on students' understanding directly into the hands of teachers, by providing quick automated diagnosis of learning for all students in a class. The Reflection test is used as an example to describe item presentation, evidence identification, and reporting to teachers, and highlight how pedagogical content knowledge can be built. [Additional funding for this project was received from the Victoria Department of Education and Early Childhood, and the Catholic Education Office (Melbourne).]