Portland may revel in its reputation as one of the “weirdest” cities in the United States, but a new study of its public school system shows that it’s also one of the most committed to dual language immersion education. A joint study conducted by RAND Education and American Councils for International Education from 2012-2015 called Study of Dual-Language Immersion in the Portland Public Schools shows significant academic gains for students randomly assigned to the immersion programs which are now located in 25% of the district’s schools.

Before we highlight five key findings related to student achievement and program quality, here’s a helpful explanation of the study’s significance and a brief look at how Portland Public Schools immersion programs are organized:

Portland Public Schools provides an excellent test bed for studying dual-language education at scale, in part because it allocates its popular immersion slots using a random assignment lottery process. Moreover, about 10% of the district’s students are enrolled in immersion, and about a quarter of its schools offer immersion programs. The 46,000-student district, which is among the two largest in the Pacific Northwest, has offered immersion since 1986, and currently offers DLI programs in Spanish, Japanese, Mandarin Chinese, Russian, and Vietnamese. These include two-way programs, in which about half of students are native speakers of English, and half are native speakers of the “partner” (non-English) language, as well as one-way programs, in which most students in the classroom are new to the partner language.

It is important to underscore that Portland Public School’s Spanish and Russian immersion programs offer 90% of instructional time in the immersion language, and 10% in English (90:10). Their Japanese, Chinese, and Vietnamese programs offer equal instructional time in English and the immersion language (50:50). Because of the benefits that accrue for students with increased time spent in the immersion language, add.a.lingua supports two models of dual language immersion education: early total one-way immersion, and 90-10 two-way immersion.

The entire study summary is well worth your time, but these five findings are particularly noteworthy:

benefits accrue with more time in the immersion language

• Students randomly assigned to immersion outperformed their peers in English reading by about 7 months in grade 5 and 9 months in grade 8.

dual language immersion programs are best for ELL students when the immersion language is their home language

• Immersion students have 3-point lower rates of classification as English Language Learners (ELLs) by sixth grade, and this effect is larger (14 points) if students’ native language matches the classroom partner language.

the cost for dual language immersion programs don’t exceed those of mainstream programs relative to their student enrollment

• Based on interviews with 14 of 19 immersion school principals, we find that school-level resources for DLI and non-DLI programs are generally proportional to immersion enrollments in a school.

majority and minority language dominant students benefit

• Immersion programs as implemented in Portland appear to be a cost-effective strategy for raising English reading performance of both native English speakers and native speakers of other languages.

consistent quality instruction takes time and effort and should be a priority if dual language immersion is to be additive in nature

• Portland’s results may depend on the levels of instructional consistency and quality that the district has been able to cultivate over time. Maintenance of quality should be a central consideration in efforts to scale or replicate such programs.

Let us know what you found of interest in the report, and contact us if addalingua can be of assistance with your new or existing dual language immersion program.