I’d like to change my approach to learning vocabulary. Even when I ask students to write definitions in their own words, they don’t seem to understand the terms. Any suggestions?
—Ryan, Fort Smith, Arkansas
High school texts may have more than 3,000 specialized terms. We want our students to understand and use this vocabulary to communicate their understanding of science concepts, but the sheer number of words plus the lack of background knowledge in younger or less experienced students can make this a frustrating experience.
Based on the work of researchers such as Robert Marzano and Debra Pickering (in their book Building Academic Vocabulary), I suggest you distill the list in the textbook to critical vocabulary: essential words important to understanding the concepts of the unit, words applicable to other units, and words specifically mentioned in your curriculum or state standards. You could also have supplemental lists of “nice to know” words and review words students should already know. For example, photosynthesis may be an essential term in a unit on plants at the upper elementary level. At the secondary level, it could be on the review list.
Traditionally, students looked up definitions in a glossary or dictionary. I observed a class in which students were copying and pasting from a website—they didn’t even have to read the text or write their own definition. A teacher mentioned that during a unit on the cell, some students had copied a definition of “nucleus” as a part of an atom. It’s important for students to understand the context in which a science word is used.
Students should have a record of the word lists in their notes. In addition to formal “definitions,” ask them to create a graphic representation of the word. Classroom word walls keep the words visible to all. I recently visited a classroom where the students had made the cards for the wall. They put the word and a drawing on one side of the card and a definition and a sentence on the back of the card. The teacher noted the cards weren’t as neat as ones she used to make, but the students had ownership in the list and some were very creative. She sometimes took the cards down and handed them out for students to review.

This teacher also displayed student-created graphic organizers, another way for students to become familiar with words. For example, using Frayer models, concept maps, or semantic feature analysis charts, students identify characteristics of the word (as well as its meaning) and show relationships between words. (These are described on the Graphic Organizers and Reading Educator websites.)
Teachers often assume students, especially older ones, know how to use context clues in the text to figure out what a word means. But with the specialized vocabulary in science, many students may need some assistance, especially less experienced students or those who are learning English. By doing a “think aloud,” teachers can model how to examine a new word using context clues or visuals. My students seemed to enjoy figuring out words using some common affixes and root or base words. For example, when my students first encountered “aquatic,” I pointed out that “aqua” is Latin for water, and we then brainstormed other words that started with aqua- and had something to do with water. They thought of Aquarius, aquarium, aqueduct, Aquaman, aquamarine. The Spanish-speaking students noted that agua means water in that language. The website Prefixes and Suffixes can help you to identify some relevant ones to share.
For students to understand and use new words, they need to hear and say them, as well as read and write them. For more complex or unfamiliar words, have the students repeat the words several times out loud, emphasizing the syllables by clapping or tapping them out: pho-to-syn-the-sis. (I picked up this idea from a colleague who taught elementary science.) This seems to help with spelling, too, so even older students can benefit.
Creating metaphors and analogies and playing games based on Password or Pictionary are enjoyable ways to explore and review words. However, I would question the value of word searches or word scrambles in helping students to use words or to understand their meaning.
You can assess students’ knowledge and use of vocabulary in interesting and creative ways, beyond an objective test. One of my favorites is a “word splash.” Using a word list (either teacher- or student-generated), the students write sentences that include two or more words. In “word sorts,” students are given lists of words to categorize. If these are done in teams or groups, the discussions student have are interesting and informative.
 
Photograph: http://www.flickr.com/photos/theglauber/416091822/sizes/l/in/photostream/