Establishing the validity of the LOCUS assessments through an evidenced-centered design approach
Abstract
This paper presents the systematic process utilized by the Levels of Conceptual Understanding in Statistics (LOCUS) project to establish content validity for assessments measuring students’ statistical understanding in grades 6-12 (ages 11-18). Evidence Centered Design (ECD) was used to develop assessments aligned with the United States’ Common Core State Standards in Mathematics (CCSSM) as well as the Guidelines for Assessment and Instruction in Statistics Education (GAISE). The ECD process began with a domain analysis based on CCSSM, GAISE, and learning trajectories from statistics education research and subsequently added layers articulating claims about student proficiency and observable evidence to support those claims. The ECD approach formalized the evidentiary reasoning by which performance on LOCUS can be used to support valid inferences about the larger domain of statistical understanding.
