This report describes the design, development, administration, quality control procedures, and psychometric characteristics of the child assessment instruments used to measure the knowledge, skills, and development of children participating in the Early Childhood Longitudinal Study, Kindergarten Class of 2010–11 (ECLS-K:2011) in the third-, fourth-, and fifth-grade data collections. The focus of this volume is the seventh through ninth rounds of data collection: the spring 2014 third-grade, the spring 2015 fourth-grade, and the spring 2016 fifth-grade rounds. (author abstract)