A randomized controlled trial (RCT) to evaluate New Mexico’s oversubscribed ​“Dual Language Immersion” charter schools, and the state’s elementary and high school charter schools as a whole

Grant Recipient: Abt Associates

Principal Investigators:

Eleanor Harvill, Ph.D., Abt Associates 

Rachel McCormick, Abt Associates

Term: 2019 — 2021

Funding: $497,494

Summary: This project is an RCT to evaluate (1) New Mexico’s oversubscribed ​“Dual Language Immersion” (DLI) elementary charter schools; (2) the state’s oversubscribed elementary charter schools as a whole; and (3) the state’s oversubscribed high school charter schools. 

All charter schools in New Mexico are freestanding — that is, they are not run by Charter Management Organizations and therefore do not follow a prescribed pedagogical and/​or operational model. However, a core group of the charters use a DLI approach, providing students with general academic instruction in both English and Spanish. DLI was previously evaluated in a well-conducted RCT in Portland’s public school system and found to produce promising effects on student reading achievement in elementary and middle school. Additionally, New Mexico has invested heavily in charter schools overall — not just DLI schools. Approximately 10% of public school students in the state attend a charter school. 

Under this project, researchers will conduct a retrospective RCT, capitalizing on oversubscribed charter schools’ admissions lotteries from prior years. The DLI study sample will include approximately 1,550 students who applied to four DLI schools between 2010 and 2014, and will measure DLI schools’ impact on 5^th grade reading achievement over a follow-up period of approximately six years. The overall elementary charter school study sample will include approximately 6,250 students who applied to 10 schools between 2010 and 2016, and will measure the charter schools’ impact on 3^rd grade reading achievement over a follow-up period of approximately four years. The high school charter school study sample will include approximately 4,000 students who applied to nine schools between 2010 and 2016, and will measure the charter schools’ impact on college enrollment over a follow-up period of approximately four to seven years. Outcomes will be measured using state test scores in reading and National Student Clearinghouse data on college enrollment.

The study’s pre-registered pre-analysis plan is linked here.

This study has been completed. A plain-language summary of the findings is available here.