English language learners (ELLs) struggle with science vocabulary every day. Unlike most native English speakers who have learned at least 12,000 words by high school (Nagy and Anderson 1984; Nation 2006), high school-age ELLs are just beginning their English learning. These students must learn everyday English, school English, and scientific vocabulary to pass examinations and meet graduation requirements.
On average, ELLs need five to seven years to catch up with their native English-speaking peers in grade-appropriate science learning (Collier 1987). My survey of New York City secondary science curricula shows that students need to learn close to 500 words in general science, over 1,200 words in biology, over 1,000 in Earth sciences, and additional words in chemistry and physics in order to pass the standardized tests and meet graduation requirements (Dong 2011, p. xv).
Vocabulary is the key to passing standardized tests, such as the Science Regents. In New York City, where I teach, one out of four public school students was an ELL in 2011 (New York City Department of Education 2011). Among ELLs, only 7% passed the Regents exams and graduated from high school on time in 2010 (Otterman 2011). By using ELLs' prior knowledge, science teachers can teach vocabulary in a meaningful and effective way and help more students to succeed in high school and, ultimately, in life.
Over the years, I have worked with both secondary preservice and inservice science teachers to develop effective vocabulary instruction for ELLs. In this article, I share three ways of using ELLs' prior knowledge to teach science vocabulary: tapping into ELLs' native language, designing culturally familiar examples, and using concept mapping.
The importance of prior knowledge
Adolescent ELLs aren't a blank slate when they enter the science classroom (August et al. 2005; Dong 2009; Dong 2011; Meyer 2000); many have had grade-equivalent schooling, acquiring native language literacy skills in their home countries. In fact, ELLs' prior learning lays an important foundation for their learning of English and scientific knowledge (Cummins 1979). Activating students' prior knowledge (i.e., the knowledge and skills a learner brings to a learning task) is a well-researched and field-tested vocabulary teaching strategy (Ausubel 1968; Rupley and Slough 2010).
ELLs who have scientific knowledge and literacy skills in their native languages can often translate these skills into English (Figure 1; Freeman and Freeman 2000; Townsend et al. 2012). For example, a student who has already learned about photosynthesis in his or her native language can transfer that prior knowledge into English to learn the vocabulary. Even ELLs who had limited or interrupted schooling can tap into their life and cultural experiences as a powerful science vocabulary-learning tool (Bruna et al. 2007).
When teaching science to ELLs, the concept of prior knowledge needs to encompass their
* native language,
* previous science learning,
* native literacy skills, and
* native cultural knowledge and life experiences.
Tapping into ELLs' native language
ELLs can often learn science vocabulary through their native languages (August et al. 2005; Dong 2011; Rodriguez 2001); cognates (i.e., words that share a similar spelling, sound, and meaning across languages) can be especially helpful. For example, the English word nucleus is nucleo in Spanish and Portuguese and noyau in French. But science teachers don't have to be multilingual to use cognates or students' native languages. Online resources, such as Google Translate (see "On the web") can provide quick translations. Teachers can also ask ESOL (English for Speakers of Other Languages), bilingual, or foreign language teachers or even bilingual students to translate key words. Figure 2 (p. 54) provides an example of a multilingual visual glossary that a preservice biology teacher prepared for a pollination lesson with a class of ninth-grade ELLs. …