This special issue of "JEDM" was dedicated to bridging work done in the disciplines of "educational and psychological assessment" and "educational data mining" (EDM) via the assessment design and implementation framework of "evidence-centered design" (ECD). It consisted of a series of five papers: one conceptual paper on ECD, three applied case studies that use ECD and EDM tools, and one simulation study that relies on ECD for its design and EDM for its implementation. In this reflection piece we discuss some of the key lessons that we have learned from the articles in this special issue with respect to the instructional utility of the digital learning environments, the nature of the statistical methodologies used, and the added value of the ECD framework for the work conducted in these projects.