Vocabulary Development in Science
Vocabulary knowledge is no doubt one of the distinguishing hallmarks of a highly
educated person. A scientifically‐literate person should have an extensive understanding of
the unique language of science. Effective science instruction therefore, involves strategies
that encourage vocabulary acquisition and development.
Question: How many words can a teacher teach in a year?
Answer: While estimates vary, researchers in education agree that at least 400
words per year can be taught and learned in one school year. On average, students
add 2,000‐3,000 words a year to their reading vocabularies.
Question: How many words can teachers teach in one lesson?
Answer: Surprisingly, there is an easy answer. Five [5] new, unfamiliar words can
be taught per lesson. Research has shown that for every word introduced after five
[5], memory overload happens and this negatively affects the learning of the five
target words.
Question: How many encounters or exposures to words are needed?
Answer: Some researchers have suggested that at least 8‐10 exposures are needed
before a new word begins to become part of a student’s lexicon. Of course, a more
accurate answer to this question would depend on the child’s background and age.
Question: What words should be taught?
Answer:
a. Content Area Words: these are terms like gravity, ecosystem, metamorphic.
b. Grade Level High Frequency Words
c. High Utility [but less frequent] Words [examples: segregate, adjustable,
creative, etc.] From: http://www.pearsonschool.com/live/assets/200728/SciAut0404586MonoFloodLapp_845_1.pdfObstacles to Vocabulary Development in the Classroom
To help students develop word knowledge in breadth and depth, we must first recognize
four fundamental obstacles, and then develop teaching practices to address those
obstacles:
• The size of the task. The number of words that students need to learn is exceedingly
large.
• The differences between spoken English and written, or “literate” English. The
vocabulary of written English, particularly the “literate” English that students encounter in
textbooks and other school materials, differs greatly from that of spoken, especially
conversational, English. Students—both English language learners and those for whom