After providing key definitions well as substantial supportive evidence for the instructional process under consideration, this analysis identifies a serious shortcoming in the way that many U.S. educators are currently encouraging teachers' adoption of the formative-assessment process--a teaching approach informed by students' en route test performances during instruction. After identifying the basics of the formative assessment process, and the manner in which reports of students' en route assessment performances should be built, it is claimed that formative assessment will attain its much-lauded learning payoffs only when short reports, easily used by both teachers and students, are routinely employed.