The "Effectiveness of Early Literacy Instruction: Summary of 20 Years of Research" study examined information about evidence-based practices that are essential for early childhood educators and policymakers as they support preschool children's language and literacy development. The study used a process modeled after the What Works Clearinghouse (WWC) methodology to systematically identify effective early childhood curricula, lesson packages, instructional practices, and technology programs in studies conducted from 1997 to 2017. The study team identified 132 interventions evaluated by 109 studies that the study team determined were high-quality experimental or quasi-experimental studies. The WWC's evidence standards are used to assess the quality of an evaluation study and the strength of its claims about whether an intervention caused the observed effect on student achievement. This document presents the following six appendixes that accompany the study: (1) The search, screening, and review process; (2) Technical results; (3) Effects of interventions by domain and outcome type for the 132 interventions evaluated by high-quality impact studies; (4) Implementation characteristics of the 132 interventions evaluated by high-quality impact studies; (5) Research basis for the 109 high-quality impact studies; and (6) Three-hundred fifty-seven studies reviewed using the evidence standards. [For the full report, see ED613947. For the Study Snapshot, see ED613950.]