Prior studies have shown that English-language learners (ELLs) score lower on standardized tests in part because of their challenges in developing background knowledge and English vocabulary. A new experimental study in the Journal of Educational Psychology examines whether an intervention designed to enhance knowledge acquisition and reading comprehension for middle school ELLs actually does those two things.

The twenty-week intervention is called PACT (Promoting Adolescents’ Comprehension of Text). It is a set of instructional practices that have been modified to include more focus on content, academic vocabulary, and peer dialogue.

The study was implemented in 2013–14 in three school districts in both the southwest and southeast of the U.S. across seven middle schools with moderate to high concentrations of ELLs. Roughly 1,600 eighth-grade students participated in ninety-four U.S. History class sections taught by eighteen teachers.

Class sections were randomly assigned to forty-nine treatment and forty-five comparison classes, such that teachers could be teaching both treatment and comparison classes. Both groups taught the same content in three units—Colonial America, the Road to the Revolution, and the American Revolution—over the same amount of time (three times a week for fifteen to forty-five minutes, depending on the week). The comparison group was business as usual, but the treatment students discussed and watched videos that provided background information relative to each unit, learned new words connected with the content, engaged in critical reading of informational text about the unit, and participated an activity where they applied their knowledge (e.g., “What might have happened to prevent the Revolutionary War?”). Study staff provided professional development and ongoing support to teachers, observed classes, and listened to audiotapes to measure implementation fidelity, as well as any spillover effects in comparison classrooms (data showed high fidelity and limited spillover). And students were administered three assessments pre- and post-intervention: a general reading comprehension test, a content knowledge test, and a reading comprehension test in the content area.

There were two key findings.

First, treatment students, both ELLs and non-ELLs, outperformed comparison students on measures of content knowledge acquisition and content reading comprehension, but not on general reading comprehension. It’s hard to know why they didn’t outperform in the lattermost area, especially since experts make a compelling case that having background knowledge makes for overall better readers. Then again, it’s also the type of reading test that good teachers loathe (read a short passage, then answer three to six multiple questions about it), so maybe it’s not a bad thing that the test failed to pick up significant differences. My colleague Robert Pondiscio, an expert in literacy, tells me that it all makes sense to him since “reading comprehension is not a transferable skill; it’s heavily dependent upon domain knowledge such that there’s no reason to think that reading about U.S. history will boost comprehension of a passage about baseball.” (Did I mention how nice it is to work with smart people?)

Second, the proportion of ELLs in classes moderated the outcomes for content knowledge acquisition—meaning that the difference between ELLs and non-ELLs in classes widened as the class gained more ELLs, particularly above 12 percent. If ELLs were between 0 and 12 percent, ELLs and non-ELLs responded comparably to the intervention. Authors say that additional supports may be needed if the ratio of ELLs increase, and they advise schools to try to keep ELLs under the 12 percent threshold so that all students can benefit from the intervention.

The bottom line is that a focus on enhancing content knowledge is advantageous for ELLs and other students, but only when measured by content-based tests. That’s good news for those of us who believe in the power of a content-rich curriculum.

SOURCE: Sharon Vaughn et al., "Improving content knowledge and comprehension for English language learners: Findings from a randomized control trial," Journal of Educational Psychology (January 2017).

Amber Northern is senior vice president for research at the Thomas B. Fordham Institute, where she supervises the Institute’s studies and research staff.  She has published in the areas of educational accountability, principal leadership, teacher quality, and academic standards, among others. Prior to joining Fordham, she served as senior study director at Westat. In that role, she provided evaluation services…

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