English-only instruction does not spur the most academic growth for English language learners entering school in kindergarten, according to new research in Educational Evaluation and Policy Analysis.Researchers Rachel A. Valentino and Sean F. Reardon of the Stanford University Graduate School of Education tracked the test scores in English language arts and math through middle school for almost 14,000 English language learners from an unnamed large urban school system. All the students in the study started kindergarten at some point between September 2001 and September 2009. A third of the students were Latino, 45 percent were Chinese and 22 percent were from other ethnic backgrounds. The researchers found that by 2nd grade, there was a substantial difference in academic performance in ELA and math depending on the instructional program the student started with in kindergarten. Second-graders in transitional bilingual programs (where the students have moved to an English-only class by 2nd grade) scored higher in ELA and math than their peers in the other instructional settings — a top ranking that they sustained through middle school. The researchers found that English language learners in English-only classes since kindergarten had the second-highest ELA scores in 2nd grade, but by 7th grade, the English language learners in dual-language programs had surpassed their English-only peers on the ELA test. The students in English-only classes as a group posted the lowest math scores in both 2nd and 7th grades.The results varied somewhat depending on the student’s native language. Spanish-speaking students in English-only classes scored the highest in ELA in 2nd grade, but by 7th grade the English-only group had plummeted to last place. Spanish-speaking students fared better in math in bilingual settings as well. Students in transitional or developmental bilingual programs fared the best in math in 2nd grade, with dual-language students catching up by 6th grade. The Spanish-speaking students in English-only classes scored the lowest in math from 4th grade through 6th grade, the final year in the study.