Often, the definitions given are rather superficial and sometimes even
misleading, as in this example. The definition offered here would work
better for ingestion than for digestion. Presumably the text itself and the
ensuing class discussion would clarify the meaning of digestion, but the
initial instructional effort probably added little to the children’s
understanding. It takes many encounters with a word in meaningful contexts
for students to acquire it.
What does it mean to acquire a word? What do we know when we
know a word? Knowing a word involves knowing something of its core
meaning. In the case of digestion, the core meaning is the process by which
the food one eats is converted into simpler forms that the body can use for
energy. But few words are unidimensional in meaning or use, so knowing a
word goes well beyond knowing a definition of it. Knowing a word requires
also an understanding of how it relates to similar forms (e.g., digestion,
digest, ingest, digestive, indigestion), how it can be used grammatically
(i.e., its word class and the grammatical constructions it can be used in), and
how it relates to other words and concepts (e.g., food, nutrient, stomach,
digestive juices, esophagus, intestines, digesting facts, Reader’s Digest).
Vocabulary instruction could be more effective if teachers understood how
words are learned in noninstructional contexts, through conversational
interactions, and through encounters with written language. Knowing
individual words more deeply is as important as knowing more words.
For children growing up in English-speaking families, rapid English
vocabulary acquisition is the rule: According to George Miller (1976; 1987),
between ages 1 and 17 children add 13 words per day to their growing
vocabulary, adding up to around 80,000 words by the time they are 17, and
very little of this is achieved with the help of teachers or dictionaries.
Vocabulary acquisition happens most easily in context and related to topics
that children care about. The teacher’s responsibility lies mainly in setting
up exposure to language in a vivid way and encouraging reading of material
that children care about.
For second-language learners, it is perhaps most valuable to stage
exposure to new vocabulary items in related groups, since many words are
more meaningful when they are understood in connection with other words
related to the same general topic (for an accessible discussion of how the
mental lexicon is thought to be organized, see Aitchison, 1994; for a
discussion of how bilinguals and monolinguals differ in their treatment of
words, see Merriman & Kutlesic, 1993). Thus talk about mothers and
fathers should include talk about brothers and sisters, grandfathers and
grandmothers; talk about buying should include talk about selling, paying,
money, and getting change. Some understanding of how translations can