The researcher investigated teacher factors contributing to English language arts (ELA) achievement of English language learners (ELLs) over 2 consecutive years, in high and low performing elementary schools with a Hispanic/Latino student population greater than or equal to 30 percent. These factors included personal teacher efficacy, teacher second language proficiency and collaboration practices of general and special education, English second language and speech language teachers. Additional factors examined were teacher use of scientifically-validated ELA practices and development of student working memory. The participants were from 16 elementary schools located in suburban counties surrounding New York City. Sixty teachers responded to a 40-item 7-point Likert scale survey instrument. Results of a t test revealed no significant differences between the individual mean scores of participants in high and low performing schools on any of the variables. A correlation analysis revealed a small inverse relationship between school type (high performing, low performing) and frequency of memory work; 8.01 percent of the variance was shared by both variables. The results of the Wald stepwise discriminant analysis revealed that the frequency of memory work accounted for 64.9 percent of the variance in predicting teacher placement in low performing schools. In conclusion, teacher reported low frequency of memory work was 3.3 times more likely in high performing schools. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]