ABSTRACT
Quality instruments consistently provide data that inform valid inferences and decisions, but the evidence necessary to establish validity for the intended uses may differ based on the types of inferences and decisions to be made. The present chapter explores validity concerns for instrument developers in terms of classroom assessment, program evaluation and improvement, and mathematics education research. Framed around key questions that developers can ask at various stages of the development process, we describe developing mathematics education instruments and their associated validity arguments in tandem. Examples of instruments to inform instructional decisions, evaluate programs, and conduct mathematics education research are integrated throughout.
