Until now, the conventional approach using two distinct groups, experimental and control, continues to dominate research, especially education research. Researchers, particularly those who are active in this domain, readily recognise this pattern when surveying literature. This article explores the use of the Solomon four-group design as a…

Several branches of the potential outcome causal inference literature have discussed the merits of blocking versus complete randomization. Some have concluded it can never hurt the precision of estimates, and some have concluded it can hurt. In this article, we reconcile these apparently conflicting views, give a more thorough discussion of what…

Context: Assessments of baseline equivalency of intervention and control groups, "balance," play a critical role in evaluating educational interventions. The highest What Works Clearinghouse (WWC) of the Institute of Educational Studies (IES) standard for educational studies, "Meets WWC Design Standards Without Reservations,"…

The purpose of this article is to describe a 40+ year journey during which researchers have endeavored to design and evaluate an integrated, empirically based reading intervention for secondary students and to chronicle the lessons learned as well as suggest future directions for this type of work. Initial development of the intervention began in…