If you are reading this, chances
are you are a habitual reader, meaning you read on average an hour or two
a day. As such, I can say with some authority, that most of the words
you know, you learned through the act of reading. Research has shown
that past the 4th grade, the number of words a person knows depends primarily
on how much time they spend reading (Hayes & Ahrens, 1988; Nagy &
Anderson, 1984; Nagy & Herman, 1987; Stanovich, 1986). In fact,
by the time they reach adulthood, people who make a habit of reading have
a vocabulary that is about four times the size of those who rarely or never
read. This disparity starts early and grows throughout life (see
M is for Matthew Effect for more on the widening disparity).
According to Beck and McKeown (1991),
5 to 6 year olds have a working vocabulary of 2,500 to 5,000 words.
Whether a child is near the bottom or the top of that range depends upon
their literacy skills coming into the first grade (Graves,1986; White,
Graves & Slater, 1990). In other words, by the first grade, the
vocabulary of the disadvantaged student is half that of the advantaged
student, and over time, that gap widens.
The average student learns about
3,000 words per year in the early school years -- that's 8 words per day
(Baumann & Kameenui, 1991; Beck & McKeown, 1991; Graves, 1986),
but vocabulary growth is considerably worse for disadvantaged students
than it is for advantaged students (White, Graves & Slater, 1990).
How important is vocabulary size?
Imagine how much harder your life would be if you didn't understand 75%
of the words you currently know. How hard would it be to read a passage
of text if you didn't know many of the words in the passage? Imagine
if reading the front page of the newspaper was like reading this passage
of text:
"While
hortenting efrades the populace of the vaderbee class, most experts concur
that a scrivant rarely endeavors to decry the ambitions and shifferings
of the moulant class. Deciding whether to oxant the blatantly maligned
Secting party, most moulants will tolerate the subjugation of staits, savats,
or tempets only so long as the scrivant pays tribute to the derivan, either
through preem or exaltation."
Would you read the newspaper
if it was all like that? Would you read anything you didn't have
to? Most non-readers have difficulty decoding the individual words,
but in addition, even if they can decode them, most non-readers do not
understand many of the words in formal text.
Vocabulary development is a lifelong
endeavor, but because of the Matthew
Effect, over time, some people develop far richer vocabularies than
other people. There have been various attempts to measure how many
words adults know, and the estimates vary widely.
Part of the reason is that it is
not clear what it means to "know" a word. Speaking personally, there are
some words I am much more familiar with than others.
Consider these words: WHITE, DOG,
and HOME
And compare them to these words:
CALLIOPE, FOP, and BRACHIAL
I don't know about you, but while
I am certain that I "know" the first group of words, I would only say that
I recognize and have some limited knowledge of the second group of words.
Dale and O'Rourke (1986) described four levels of word knowledge, which
they characterized with four statements:
1. I never saw the word before
2. I've heard of it, but I don't
know what it means
3. I recognize it in context, and
I can tell you what it is related to
4. I know the word well
It is hard to say how many words
I know well, much less how many words I'm somewhat or vaguely familiar
with.
Also, estimating the number of words
a person knows depends on what counts as a word. If DRIVE, DRIVER, DRIVES,
DRIVEN, and DRIVING all count as separate words, then the estimate would
be considerably larger. Carroll, Davies, and Richman (1971) created
a database of English words that appear in print by counting the number
of occurrences of every string of letters that was separated by a space
on each side (they sampled some 5,000,000 words from a variety of published
texts). They came up with 86,741 unique "words," but, because a computer
did the counting, every unique letter string was counted as a separate
word -- DRIVE, DRIVER, DRIVES, DRIVEN, and DRIVING were all counted as
separate words. Also, because a computer did the counting, misspelled words
were counted (this was 1971 -- before spell-checking), and things that
we would not recognize as words were also counted (e.g. "G787" and "FI--").
Toss out the misspelled and nonsense words, and you are closer to 50,000
unique "words."
It is reasonable to say, then, that
a literate adult knows somewhere around 50,000 words, if you count DRIVE,
DRIVER, and DRIVES as separate words. But as I said, literacy and
volume of reading is highly correlated with vocabulary size (e.g. Nagy
and Anderson, 1984), so an adult that does not read habitually would have
a much smaller vocabulary than an adult that reads voluminously.
Nagy and Anderson (1984) estimated that an average high school senior knows
45,000 words, but other researchers have estimated that the number is much
closer to 17,000 words (D'Anna, Zechmeister, & Hall, 1991) or 5,000
words (Hirsh & Nation, 1992). Surely these dramatically different
estimates depend upon the three questions described above, namely, what
does it mean to "know" a word, what counts as a "word," and who counts
as "average?"
What is not at all in doubt, however,
is this. People who habitually read from a wide variety of texts
have much, much richer vocabularies than people who do not read much.
And people who have richer vocabularies find it easier to read challenging
texts than people who do not have rich vocabularies. That is the
conundrum -- you need a rich vocabulary to read widely, and the best way
to develop a rich vocabulary is to read widely. Thus, vocabulary
size is both a cause of and a consequence of reading success.
So where do you start? Ideally,
you start at a young age. Children who are given lifelong support
for literacy skills tend to build on their successes and flourish.
Children who are still struggling in the second or third grade typically
continue to struggle throughout their lives unless dramatic intervention
is taken.
Ideally, some day, all students
will learn to read successfully at a young age, but for now, there are
many older struggling readers who do not have very large vocabularies.
If you have a student who is not reading well, and who thus does not read
habitually, how can you enhance their vocabulary (thus making it easier
for them to read habitually)? Is it possible to teach vocabulary
directly?
Research studies suggest that it
is possible to teach vocabulary out of context, but it is not very efficient.
It is possible to teach children between 300 and 500 words a year (8 to
10 words a week) through explicit context-free instruction, but that pales
when compared to the 3,000 words a year that literate children learn throughout
their school years (Nagy & Anderson, 1984). And Stahl & Fairbanks
(1986) found that directly teaching children dictionary definitions for
words did not enhance their comprehension of a passage of text containing
those vocabulary words. The definition of the word only provides
a superficial understanding of the word, and the level of word knowledge
necessary to enhance comprehension is deeper than mere definitions.
Unfortunately, research has shown
that the best approach to teaching vocabulary is to teach children some
strategies for learning the meaning of words in context, and then encourage
them to read voluminously and from a wide variety of texts and genres (Kuhn
& Stahl, 1998). Teachers can also help students to develop a
deeper understanding of words through some direct instruction that involves
talking about the definitional and contextual meanings of words, focusing
on synonyms and antonyms, providing examples and non-examples, and discussing
the subtle nuances and differences that make synonyms somewhat different
(e.g. the difference between kill and murder has to do with intent and
crime. You can't murder a pig or a deer, and you can't accidentally
murder a person.)
Children also need to encounter
words frequently in a variety of contexts in order to internalize them.
McKeown, Beck, Omanson, and Pople (1985) found that children did not really
know and understand words they had only encountered four times, but they
did know and understand words they encountered twelve times. Teachers
can be strategic about introducing new vocabulary to students repeatedly,
and providing a rich discussion and analysis of the words to enhance understanding.
And finally, I would personally
argue that it is important that students play a very active role in vocabulary
development. There are many words that I have passively read in context
repeatedly, but I became much more familiar with those words when I actively
used them in my writing. Every day, I receive an e-mail from the
"word a day" service that features a very rare and unusual English word.
Every day, I dutifully open the e-mail, and read the word and its definition.
But the only words that stick with me are the ones that I actually use
in my writing. A few days ago, I happened to get the word "idiopathy"
at a time when I happened to be writing an essay about different forms
of dyslexia. The word "idiopathy" was perfect for describing certain
forms of acquired dyslexia that have no known origin or source. Now
I have internalized that word, but there are probably 300 words that have
been e-mailed to me by this service in the past year that I have never
used again, nor would I understand if I encountered them in context.
Typically, to make a word part of my personal lexicon, I need to actively
use the word in my writing and speech, and I need to use it on more than
one occasion. I would argue that vocabulary instruction should be
designed with that in mind.
For more on the subject of vocabulary
instruction, I strongly encourage you to read Steven Stahl's excellent
book, "Vocabulary
Development." This is a very short but highly informative book
that describes research findings and has suggestions for classroom instruction.
References:
Baumann, J.F. and Kameenui, E.J.
(1991). Research on vocabulary instruction: Ode To Voltaire. In J. Flood,
J.J. Lapp, and J.R. Squire (Eds.), Handbook of research On teaching the
English language arts (pp. 604-632). New York: MacMillan.
Beck, I.L. and McKeown, M.G. (1991).
Social studies texts are hard to understand: Mediating some of the difficulties.
Language Arts, 68, 482-490.
Carroll, J.B., Davies, P., and Richman,
B. (1971). The American Heritage Word Frequency Book. Houghton Mifflin,
Boston.
Dale, E. & O'Rourke, J. (1986).
Vocabulary building. Columbus, OH: Zaner-Bloser.
D'Anna, C.A., Zechmeister, E.B.,
& Hall, J.W. (1991). Toward a meaningful definition of vocabulary
size. Journal of Reading Behavior, 23, 109-122.
Graves, M.F. (1986). Vocabulary
learning and instruction. In E.Z. Rothkopf (Ed.), Review of Research in
Education, 13, 49-89.
Hayes, D.P. and Ahrens, M.G. (1988).
Vocabulary simplification for children: A Special case of "motherese"?
Journal of Child Language, 15(2), 395-410.
Hirsh, D. & Nation, P. (1992).
What vocabulary size is needed to read unsimplified texts for pleasure?
Reading in a foreign language, 8, 689-696.
Kuhn, M.R. & Stahl, S.A. (1998).
Teaching children to learn word meanings from context: A synthesis
and some questions. Journal of Literacy Research.
McKeown, Beck, Omanson, and Pople
(1985)
Nagy, W.E. and Anderson, R.C. (1984).
How many words are there in printed English? Reading Research Quarterly,
19, 304-330.
Nagy, W.E. and Herman, P.A. (1987).
Breadth and depth of vocabulary knowledge: Implications for acquisition
and instruction. In M. McKeown and M. Curtis (Eds.), The Nature of Vocabulary
Acquisition, (pp. 19-35). Hillsdale, NJ: Erlbaum Associates.
Nagy, W.E., Herman, P., and Anderson,
R. (1985). Learning words from context. Reading Research Quarterly, 19,
304-330.
Stahl, S.A. & Fairbanks, M.M.
(1986). The effects of vocabulary instruction: A model-based
meta-analysis. Review of Educational Research, 56(1), 72-110.
Stanovich, K.E. (1986). Matthew
Effects in Reading: Some consequences of individual Differences in the
acquisition of literacy. Reading Research Quarterly, 21, 360- 407.
White, T. G., Graves, M. F., and
Slater, W. H. (1990). Growth of reading vocabulary in diverse elementary
schools: Decoding and word meaning. Journal of Educational Psychology ,
82 (2), 281-290.
