The goal of the English Language Learners Research Alliance (ELLA) is to collaborate with states, districts, and schools on the use of data to identify and understand the diversity of their English Language Learner (ELL) population along a range of demographic factors, such as educational background, cultural and linguistic characteristics, socio-economic status, and special education designation and their equally diverse learning needs. In 2012, the ELLA Core Planning Group (CPG) engaged in a research agenda setting workshop designed to craft a five-year program of work to achieve the goal described above. This program of work was intended to provide direction for current and future projects that would build a body of related research focusing on quality education for the diverse ELL populations in our region. Over the past two years, the research agenda has evolved to focus on two key topics that are presented and described in this report: (1) Student Characteristics and Implications for the Design of Programs and Services; and (2) ELL-Related Professional Development for Educators.