k, 1987).
Reading Comprehension. The WORD Reading Comprehension scale
(Wechsler, 1993) measures the student's understanding of short
written passages of text. With this test, the child reads a passage out
loud or silently and then answers comprehension questions posed orally
by the examiner. The measure has a split-half reliability for children
age 15 to 16 of .82
Spelling. The BAS II Spelling scale (Elliott et al., 1997) provides
a number of phonetically regular and irregular words to assess the
child's ability to produce correct spellings. Each item is first
presented in isolation, then within the context of a sentence, and then
again in isolation. The child has to respond by writing the word:
reliability, .91; validity with WORD Spelling (Wechsler, 1993), .63.
Written Language. The WOLD Writing Expression test (Wechsler, 1996;
Rust, 1996) requires children to write a letter describing their ideal
house. Children are allowed 15 min to complete the task. The written
output can be scored either holistically or analytically: reliability,
.89, correlation with Woodcock-Johnson Psycho-Educational
Battery-Revised (Mather & Jaffe, 1996) Dictation = 0.72. The
analytic scale comprises six dimensions, each rated on a 4-point scale,
which are scored independently of each other: ideas and development;
organization, unity and coherence; vocabulary; sentence structure and
variety; grammar and usage; and capitalization and punctuation.
Writing Fluency. Our handwriting fluency task (based on Berninger,
Mizokawa, & Bragg, 1991) requires students to write out the letters
of the alphabet, in lower case, in order; as quickly as possible in 1
min. Letters are only counted towards a total number of letters per
minute if the letters are in the correct order and legible. The task has
an interrater reliability of r = 0.97 (Berninger et al., 1997). It has
been incorporated into the Process Assessment of the Learner[TM]
(PAL[TM]) Test Battery (Berninger, 2001), where it has been shown to
conform fully with psychometric standards of reliability and validity.
Schools, parents, and participants provided informed consent prior
to any testing. A qualified educational psychologist assessed each
student individually in a quiet room at school over 3 days. The first
session involved a familiarization with the assessor and a discussion
about the longitudinal study. Participants were allowed to terminate the
session or opt out of a test if they wished. All tests were administered
using the standard procedures in the manuals. Participants received a
certificate of merit for participation in the study.
For the writing measure (WOLD; Wechsler, 1996), assessors noted the
time taken to produce the written text in seconds and participants were
asked to read back their written texts to prevent penalizing children
who were poor spellers; Unclear words were noted on a separate sheet.
Two research assistants performed reliability checks for the six
dimensions of the analytical scoring of the WOLD. In the case of an
interrater disagreement, the scores were further discussed with the
research team and informed the final scoring of the texts. Mean
interrater reliability for a randomly selected 36 ratings was 80% with a
Kappa score of .66. The research assistants counted spelling errors and
the total number of words produced, excluding numerals. There was 100%
agreement between raters for these measures.
We report data only for children completing the writing measure at
age 16 (N = 58). To normalize performance on the test we transformed
each standard score, the centile or T score, to a z score to provide a
common metric for analysis. In this section, we first examine student
performance in written text production, both on the total analytic score
of the WOLD (Wechsler, 1996) and in terms of words written and errors
produced. We then describe the relationships between language and
literacy and the total analytic score on the WOLD. To consider further
the different relationships between the variables, we present two path
analysis models to examine the magnitude and signi