As many as 18% of eligible Arizona students could be denied English language services to which they are entitled if a single home language survey question is used to identify potential English language learners (ELLs), according to a new study released by Stanford researchers.

Stanford Education Professor Claude Goldenberg and doctoral candidate Sara Rutherford Quach analyzed data of Arizona's home language survey from two metropolitan districts. They found that Arizona's recent sharp reduction in the home language survey questions—from three to one—can lead to failure to identify students who, by the state's own criterion, are entitled to English language services. They estimate that as many as 11 to 18% of students could be under-identified.

"By excluding from English proficiency testing students whose parents answer English as the language the student speaks most often, limited English proficient students are certain to be under-identified," the researchers wrote. "As a result, students who are likely to need ELL services will not receive them."

Goldenberg and Rutherford Quach also found fault with Arizona's current fail-safe system, in which teachers can nominate initially overlooked students who might need ELL services for language proficiency testing. They found it highly unlikely that the system will successfully identify most students that the survey fails to identify.

In July 2009, the Arizona Department of Education (ADE) reduced the number of questions on its home language survey, which parents are asked to fill out to help the district identify potential English language learners who might qualify for school services.

The study is one of nine released last week by The Civil Rights Project/Proyecto Derechos Civiles at the University of California at Los Angeles on the condition of English learner students in Arizona. A total of 21 senior scholars and advanced graduate students from UCLA, Stanford, Arizona State University, and the University of Arizona joined together to produce the nine studies in order to examine how Arizona's English language learners are faring under the state's current educational policies.

A PDF of the full study is now available on The Civil Rights Project's website.