Reading Volume
as a Contributor
to Growth in Verbal Skills
In several studies, we have attempted to link
children’s reading volume to specific cognitive
outcomes after controlling for relevant general
abilities such as IQ. In a study of fourth-, fifth-,
and sixth-grade children, we examined whether
reading volume accounts for differences in
vocabulary development once controls for both
general intelligence and specific verbal abilities
were invoked (Cunningham & Stanovich,
1991). We employed multiple measures of
vocabulary and controlled for the effects of age
and intelligence. We also controlled for the
effect of another ability that may be more closely
linked to vocabulary acquisition mechanisms:
decoding ability. Decoding skill might mediate a
relationship between reading volume and a variable
like vocabulary size in numerous ways.
High levels of decoding skill, certainly a contributor
to greater reading volume, might provide
relatively complete contexts for figuring
out the meaning of words during reading. Thus,
reading volume and vocabulary might be linked