reading time (less than a minute daily). Or, to
take another example, the child at the 80th percentile
in amount of independent reading time
(14.2 minutes) was reading over twenty times
as much as the child at the 20th percentile.
Anderson et al. (1988) estimated the children’s
reading rates and used these, in conjunction
with the amount of reading in minutes per day,
to extrapolate a figure for the number of words
that the children at various percentiles were
reading. These figures, presented in the far
right of the table, illustrate the enormous differences
in word exposure that are generated by
children’s differential proclivities toward reading.
For example, the average child at the 90th
percentile reads almost two million words per
year outside of school, more than 200 times
more words than the child at the 10th percentile,
who reads just 8,000 words outside of
school during a year. To put it another way, the
entire year’s out-of-school reading for the child
at the 10th percentile amounts to just two days
reading for the child at the 90th percentile!
These dramatic differences, combined with the
lexical richness of print, act to create large
vocabulary differences among children.